PipeBoost, who sell compression software for IIS, has a nice "compression checker" tool:
http://www.pipeboost.com/GetReport.asp? ... s/beast.js
It's reporting an uncompressed size of 303,618 bytes, and a compressed size of 71,775 bytes. Considering that the gzip modules of most webservers (lighty, at least) have zero overhead on compressed static files due to caching, not a bad improvement
Google makes a javascript compiler called Closure that seems to be the most efficient "javascript compressor" available (tests show it beats out YUI and jsmin, at least). In advanced mode, where it gets aggressive with optimizations which may or may not require code changes to use, it reports:
117.56KB (36.99KB gzipped)
In simple mode, which is safer in terms of not requiring code changes, but is less efficient:
162.92KB (43.98KB gzipped)
So, with little effort on your part, Closure gets your javascript down from 70KB to 44KB. With some effort on your part, it can help you get down to 37KB.
Here's the link:
http://code.google.com/closure/