HimOrHer is an attempt at GenderNeutralLanguage. That page is currently, slowly being refactored to make sense out of a threaded mess, but it contains many good points and sensible discussion. Various alternatives are offered and debated, while others suggest that this really isn't a problem and that people should just GetOverIt. Perhaps anything that gets in the way of communication is better avoided, so adopting a single, consistent alternative would be a GoodThing. The evidence suggests it will be a long time coming.
One observation perhaps worth repeating is that one author, name unknown, would apparently abbreviate "He or she/it" as H'or'sh'it.
An extensive scholarly discussion of this topic justifying the use of the singular "their" can be found at http://www.crossmyt.com/hc/linghebr/austheir.html#X1a
Linguistically, this is an easy subject: many languages have "gender" in their grammar/morphology. In general, "gender" has nothing to do with male/female, it's just a category like plural or verb. In English and other languages descended from Proto-Indo-European, "gender" happens to be a three way opposition of male/female/neuter; in English, this is vestigial and remains only in pronouns. In some other languages, it is a two way contrast between living/non-living. In many languages, it is too complicated to explain to a non-speaker in any way.
But above all, it is arbitrary and an accident of history for any given language. Languages that do not have a male/female opposition in their grammatical genders do not have any kind of better track record in how that culture treated females. There is no correlation at all (they all tend to be equally bad, one might say).
Not entirely true. Finnish lacks grammatical gender ("h�n" means either "he" or "she"), and Finland was the first country in Europe to grant women's suffrage (1906, see http://en.wikipedia.org/wiki/Women%27s_suffrage ). Of course, the correlation between these facts is questionable.
In the twentieth century, it became politically popular to pretend that English grammatical gender, as reflected in words like "he" and "him", had some kind of political and social agenda, and reflected the archaic domination of females by males. However, not only is there no scientific support for this thesis, there is a large amount of evidence that the claim is scientifically incorrect.
On the other hand, some people are aware of this, and still choose to try to change their own English usage, in order to show solidarity for women's rights or some similar political or social agenda. That is reasonable.
What is unreasonable is to insist that the English language oppresses women, and that therefore other people must switch away from the previous grammatically correct utterances, and start using... well, no one quite knows what to use. This is linguistically unjustified. There is nothing evil about sticking with traditional usage. There are alternate ways to support things like equal rights. Like voting.
-- DougMerritt
Doug, there is large body of academic and organizational theory and practice that does not support your contention. If "traditional" usage did not contain a political or social agenda - or less strongly, if it did not contain information or content - then we would not notice when it was changed. There is a wealth of data, some anecdotal and some rigorous, that demonstrates the effect of the pervasive use of the masculine pronoun. We have seen some of those episodes here, where the entire tenor of a page changed when the pronouns were changed from "he" to "she". If such a change had no information or connotation, then we would not react so strongly to it. The history of various revisions of English translations of the Bible and of religious liturgy (such as the 1979 revision of the Episcopal Book of Common Prayer) demonstrates how deeply the political and social agenda permeates such texts.
Further, it is specifically because the English language (in contrast to others) does not assign a gender to nouns that pronouns such as "he" and "she" communicate gender content in English passages. It strikes me that a claim that the "English language oppresses women" is a StrawMan - that is not the claim that I hear or read being made. The claim is, instead, that the consistent and biased use of gender-specific pronouns reinforces stereotypes that oppress women. In German, French, Italian, Spanish, and similar languages that categorize nouns by "gender", the grammar of the language requires that a consistent "gender" also be applied to various language elements that reference nouns. I quote "gender" because the language scholars I know say that even the use of the term "gender" is misleading - it is really simply a structural device to join modifiers and their objects. I agree that such grammar does not, in itself, constitute an "oppression" (although feminists in Germany, France, Italy and Spain strongly disagree). In the case of English, however, there is no such requirement for a bias. The pronouns "he" and "she" (and "his" and "hers" and so on) do contain information about the gender of their referents, are not required by the grammar and syntax of the language, and can be readily avoided with a little extra attention.
Finally, it is commonly reported from those organizations and people who have experienced it that the effort of finding gender-balanced alternatives to biased passages does, in fact, reveal a great deal about the pervasive and often unconscious biases that we commonly share and that such passages reveal.
-- TomStambaugh
Believe it or not, despite considering myself somewhat of a feminist, I agree that English does not oppress women (not womyn, please not womyn), people oppress people. The end. As someone who fiddles with words, I find that it's easier to do that than it is to really change things. Political Correctness started out as a good idea - everyone should be referred to in a manner that makes them comfortable - but it seems to me that we have focused on messing with the words now, not with the attitudes that underlie them. Others I have had this argument with have suggested that by changing the words, we are changing attitudes, but I really don't think so.
The ideal solution to the him or her/he or she issue would be to come up with an entirely new gender neutral pronoun - people have tried with their, but it's sort of awkward - but then how to do invent that word and, thornier,how do we get everyone to use it, let alone get them to agree on what it is? As someone studying to be a TechnicalWriter I've heard the issue discussed quite a bit. Even the experts don't seem to agree on a good solution. One of my favorite books on grammar and usage Style: TenLessonsInClarityAndGrace, calls the he/she solution awkward - I agree - and while a text I read on editing recommends either the he/she solution, or if possible rewording passages so that there is no need to use a gendered word at all. Many times, it is feasible to just rephrase to exclude a mention of gender, for instance, "To provide less instruction than a child needs would deny him the opportunity to master a skill that he must have in order to progress in independent reading", can be changed to read "To provide less instruction than needed would deny the student the opportunity to master a skill necessary in order to progress in independent reading" without hurting the meaning. In cases where it isn't feasible to rephrase I tend to alternate gender pronouns between sentences throughout the document so that one sentence, or example refers to a male, and the other refers to a female so the result is something like this, "A successful writer needs to sure he makes time to write every day. However that doesn't mean that she doesn't feel despair when faced with a blank screen each morning".
Just for the record and the sake of completeness, the editing text I mentioned recommends seven ways to handle the gendered language issue:
See also SingularThey (ReferctorMe?: merge with)