Speedtalk is a fictional constructed language and key plot device in Robert A. Heinlein's novella Gulf (1949). Speedtalk is a logic-based language with complex syntax, minimal vocabulary, and a rich phoneme inventory (written with letters such as œ, ħ, ø, and ʉ); it would make both communication and thought more efficient and precise. A single phoneme indicates a word, so a "word" indicates a sentence. In the only example given, a single word means "The far horizons draw no nearer."
Examples of Speedtalk 
Two untranslated conversations appear in the story:
"œnɪe ʀ ħøg rylp"
"ɨpbitʹ New Jersey."
Attempts at creating Speedtalks 
As the idea is outlined but not developed in Heinlein's work, many have attempted to create languages embodying Speedtalk's principles.
- Basic English claims to have reduced English to 850 basic words, but only by exploiting English-speakers' extensive vocabulary of homonyms and idioms
- The built-in redundancy of natural languages allows utterances to be understood in spite of not being clearly heard
This first point has been made somewhat irrelevant by the comments of Ben Sandler in his article "Speedtalk".