Dutton Speedwords are a planned language designed to increase the efficiency of speaking and writing, and some allege that it can serve the same purposes as EsperantoLanguage of bridging cultural gaps, et al. Of course, in reality, it seems to be simply a refactored EnglishLanguage with irregularities removed, words compressed, and a crude system of root words and affixes.
It does have some good ideas, for example, that most-often-used words should be the shortest. In Esperanto, all forms of the verb "to be" are two syllables: esti, estas, estu... In Speedwords, there are plenty of one-letter words, for example: the = l; (why do you need 'the' anyway?) of = d; and = &; to = a; in = i; a = u; that = k; is = e; was = y; he = s.
While it hasn't caught on in the speaking community, it is said that many people use Speedwords as writing shorthand.
One homepage: http://www.reocities.com/Athens/Delphi/2464/
More discussion of Dutton Speedwords and Emacs AbbrevMode?: http://www.ludism.org/mentat/ShorthandSystem
I've also seen some articles about "speedwriting", a simplified form of English for speedy handwriting without having to learn a formalized shorthand; for example, "the" is a single dot and the "th" sound in other words is a dash.
A small 1960s era book titled 'Notescript' ( http://zhurnaly.com/cgi-bin/wiki/HandOfOnesOwn ) espoused a simple but effective speedwriting system. Much of it was based on dropping redundant letters ("cn u rd ths?") but it also employed shape-suggestive script elements to represent very common words or letter combinations - e.g., '/' denoted 'and' and '\' denoted 'the'. Some letter combinations were restyled to eliminate initial, intermediate or final strokes, particularly in common prefixes or suffixes. The latter part of the book developed a variation on the method for taking typed notes. Notescript helped me transcribe lectures verbatim in highly technical graduate courses such as Electromagnetics or Stochastic Processes.