An article on writing for machine translation in Japan Today (web archive copy)
Sun Microsystems have developed a system called Sun Proof, which checks text intended for machine translation and flags up possible problems. It is described in a Sun Microsystems Newsletter (web archive copy).
CLAT (Controlled Language Authoring Technology) is a method of writing technical manuals using a limited vocabulary and limited forms, to make automatic translation easier.
The development and use of machine translation systems and computer-based translation tools
http://dmoz.org/Computers/Software/Globalization/Computer_Aided_Translation/
The Translate and Back website will translate your text into another language, and then back again to see if it still makes sense. The utility also contains virtual keyboards and supports right to left languages.
Updated 2011-05-09