Caching

[Minoru]

With RSS feed, we can now expect an influx of traffic: RSS readers check feeds as often as once in a few minutes. And while it's not too big a strain for client to download 20Kb of XML every now and then, the server will certainly notice.

All these problems can be solved if we start setting ETag and Last-Modified headers in the responses (and processing If-None-Match and If-Modified-Since headers in requests).