Just a thought: RAM costs money. Reboots are free. I wish I'd remember that. I'm on a fixed income so frugality is a necessity.
I just noticed many of us are using Snow Leopard. I'm afraid my brief love affair with Lion is over. I really liked Leopard, and I was getting along fine with it even after Apple stopped supporting it. Recently, when I couldn't get a Flash update after the recent security issue, I decided I had better move on. I upgraded my Leopard to Snow Leopard, then to Lion, but had some performance issues. I created a DVD and did a clean install of Lion. Didn't improve it. So I tried a clean install of Snow Leopard then upgrade to Lion. Sadly I'm still not happy with it. I have 10.7.4 with all the software updates. I suppose I could live with the other changes, but the Finder keeps searching on partial strings while I type the search terms, which causes it to hang. It can't get out of it's own way. Plus it just can not remember my Desktop Background. I'm tired of waking up to the Andromeda Galaxy every morning. I'm "downgrading" to Snow Leopard.
Maybe my resources are a little light for Lion, but according to MacTracker I'm maxed out.