I'm a big advocate of gzipping the web. People should be aware that enabling gzip can cause some differences with page rendering due to the extra decompression step. It also increases CPU load on the server. There can be other minor issues too. No show-stoppers though.
Also, the percentage of compression savings should not be confused with the savings in load time. An 80% reduction in the size of the response does not mean an automatic 80% reduction in page load time.
Mmm...I don't know how easy it'd be for you to get a precompiled C++ extension hooked into Arc. Something Guile-ish? But yeah, once that's done, just toss everything your server outputs into it.
Perlbal (or something else) proxying requests would be a quick way to add support. Probably not worth the hassle on news.yc. No pages are that big and I doubt bandwidth usage is killing you.
currently this page is scoring an 82 on YSlow. Needs to make use of a CDN. Needs to add expires headers to external resources, and Needs to Configure ETags.
Really, what does YC need a CDN _for_? Just because YSlow says it doesn't mean it's actually a sane idea. They also say to turn off ETags, when what's actually good advice is to set up ETags in such a way that it works.
Also, the percentage of compression savings should not be confused with the savings in load time. An 80% reduction in the size of the response does not mean an automatic 80% reduction in page load time.