One thing I've noticed where all modern browsers fall short is caching. I remember years ago in Internet Explorer 5 - a browser that was the horrors by todays standards! - that I could select "File/Offline Mode" at any time, and then browse everything I visited in the last couple of days from cache. It would even automatically activate offline mode when the connection went down. Also it seemed to use the cache much more aggressively than nowadays even when browsing online. All of this was a neccessity with the modems of the day and their slow and unreliably connections. Nowadays, when I'm travelling with my netbook I could frequently use such a feature, especially when WiFi is flaky or not available.
Firefox still has an option to "work offline", and it works on a handfull of pages, but it seems very limited. Also there is no straightforward way to see which sites in my history are cached.
Is there a way to make caching more "agressive" or comprehensive, and offline mode useful again? Maybe extensions, or a certain browser?