I just use Firefox (currently 3.6b4) with a few addons, and don't do anything special at all. Memory usage tends to be 600-700 MB, which isn't enough for me to

I just use Firefox (currently 3.6b4) with a few addons, and don't do anything special at all. Memory usage tends to be 600-700 MB, which isn't enough for me to care. I'm not sure what you mean by "lag" -- I don't use any web apps, so there's very little background stuff running.