Finding Firefox resource hogs that freeze or slow it down

Question

Possible Duplicate:
How to Determine which Firefox Add-ons are Using the Most Memory

I know I have many extensions (50+). Too many, perhaps (case in point). However, I am willing to pay for using so many with a slower Firefox.

However, some extensions slow it down TOO MUCH, to the point of freezing. While having a lot of extensions indeed slows me down, it's those 1 or 2 that completely kill it that I was to find.

Chrome already has a taskbar-like monitor for internal processes, and IE promises the same in the future. So how can we do the same in Firefox?

Specifically, how do you find which extension is hogging those resources and freezing the app? If it's a script (js, XUL?) that's killing it, how could I trace it? Maybe an extension that shows the currently running script/XUL process/subprocess/whatever - then when a freeze occurs, the name of the process would be frozen with it? What about tracing the memory usage from each extension?

I definitely do not feel like restarting Firefox disabling extensions one by one, especially since the freezes start to occur after Firefox has been running for some time.

Thanks.