Hmmm, let’s see if this entry gives a boost to Google and friend for what has been a simple solution to a very obnoxious problem: using Firefox under OS X has been a major pain lately, with random crashes and nearly constant 100% CPU occupation.
Not feeling like getting back to Safari, I started googling around and after a while I found a long running issue with Flash movies, who tend to eat all the available CPU time. Installing
Flashblock seems to have cured the issue, and I’ve been using Firefox all day long without a hitch. YMMV, of course, but I’m an happy puppy again.

I “switched” to Safari and I’m happy with it. I only use Firefox for the webdeveloper plugin.
-Dieter
Blocking Flash
Gianugo forgets to mention another Great use of Flashblock not seeing the ads!
But i prefer using the flashblocking CSS code from Floppymoose
/* Prevent flash animations from playing until you click on them. */
object[classid$=”:D27CDB6E-AE6D-11…
You might like to try Deer Park (Firefox alpha), which I’ve found to be much better-behaved under Tiger. Check it out at http://www.mozilla.org/projects/deerpark/releases/alpha2.html
Thank you, thank you, thank you!