Since I upgraded to FF3 I've found it far less of a resource hog than all previous versions I've used. Mem usage has rarely topped 100Mb compared to the frequently occuring 700+, it releases RAM when I close tabs (unlike before) and it's been more stable with only a couple of 'unexpected error' crashes.

Oh, and I won't be trying Chrome. If it's anything like Google Desktop then I don't want my system being interrogated / uploaded / spied on, without my permission.

I get called out too PC's that slow to a crawl,  remove the Google Desktop and back to full speed that really does screw performance up.