I'm the kind of geek who has lots of tabs opened almost all the time. They are either search results, or "ephemeral bookmarks" (pending reads which could turn into permanent bookmarks if they prove to be interesting), pending tasks, or always-open applications (GMail, Google Calendar, ...), and thus having from 10 to 30 tabs open is not uncommon.
The problem: I use Firefox. No, no, wait, I like Firefox! Not that much, but can't work without its extensions anyway. Back to the problem: it is very known that Firefox performance goes down very quickly when (ab)using a lot of tabs. It eats memory and CPU like hell.
Well, some time ago I found a very easy way to get the CPU consumption level down: the FlashBlock extension. It stops the execution of flash apps until you explicitly click them.
Most of the Firefox CPU consumption here turned out to be flash ads using my CPU to do annoying animations on which I couldn't care less. So FlashBlock is a good way to kill two birds with one shot.