I had 6 windows and more than 40 tabs open. The browser had not been restarted in the last 3 days. Not surprised because I already have so many extensions installed as well. This is the maximum consumption of RAM I have ever noticed on any machine with 1 GB physical ram.
use opera man!!!
I had the same problem for the longest time, but switched to opera. I Usually have anywhere from 1-50 tabs open per session (opera allows tab/window session saving-for future retrieval)
have it running on windows and mac os x for a year- no problems
cheers