Paul Buchheit points out that gzip makes any web app faster. (All apps deployed to Heroku automatically compress pages they serve, by virtue of passing through Nginx’s gzip filter on the way out.)
Client-side, RestClient asks for gziped content, and decodes it for you automatically. This doesn’t matter for most API calls (gzip won’t get significant savings for a small JSON or XML body), but in certain cases it makes a big difference.
And, oh yeah: gzip makes javascript minification irrelevant. Don’t minify, gzip.