There's a program on freshmeat called email2sms (http://freshmeat.net/projects/email2sms/) that runs emails through a series of filters until they're short enough to be sent to a cell phone as a SMS message -- which typically have a maximum length of 150 characters. The script is mostly just a wrapper around the nifty Lingua::EN::Squeeze Perl module.
Squeeze takes English text and shortens it aggressively using all manner of abbreviations. It leaves the text remarkably readable for being about half its original length.