Ok.. this may be silly. And I feel silly for asking since I'm paid to answere these sort of questions. But I'm stumped.

What in the world is causing firefox to consume this much memory?

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
32135 dennis 20 0 1293m 178m 11m R 50.5 9.2 14:50.48 firefox

1293m of virtual memory. Then, after closing facebook, it dropped back down to near nothing. When loading it again, it went right back up to 1300m virtual.

Am I missing some obvious tuning parameter or something that can stop it from hogging so much memory, no matter what the web page wants?

There are few things you can do to get a little better performance, disable auto scrolling and smoth scrolling, also disable hardware acceleration on flash settings, that should help a bit.

Now here some things you should know about facebook:
It isn't your friend: http://www.guardian.co.uk/commentisf...ot-your-friend
It is a surveillance tool: http://articles.timesofindia.indiati...nt-protection/
It is sharing private user communications with NSA: http://www.naturalnews.com/040659_in...#ixzz2WBDZI1dn
And has been leaked out: http://www.alternet.org/civil-liberties/whistleblower
Richard Stallman is talking about it for a very long time: http://stallman.org/facebook.html

Cheers