Hi, I'm running Slack 12.1 (2.6.24.5) on a Thinkpad X61s, and run powertop to try to learn how to reduce my wattage / increase battery life.

The first thing that has been jumping out at me is this 220 wakeups caused by "ohci1394, HDA Intel, and wifi0" (96%, 220 wakeups from idle). When I unload the ohci1394 and snd_hda_intel modules, and re-run powertop, only the wifi0 remains and it's still causing about 96% and 220-ish wakeups, so it seems like the wifi0 is the culprit.

My wireless card is an Atheros AR5212 using madwifi... is it a known problem that madwifi causes this many wakeups? Is there a way to reduce it?

there is a madwifi wiki and a whole community behind it...
google for it?

The reason I'm asking here is because... I have been googling and searching the madwifi mailing lists, to no avail. So I thought maybe you folks would have heard about this issue.

It seems that atheros/madwifi don't even support power saving modes...

I think I'm just going to get the intel 4965agn card in it instead of the atheros and see how it goes... then i could make full use of the wireless n router.

I'm quite ingnorant for powersaving matters since i mostly use my setups as APs (ddwrt) and servers (RT61/rt2500).
I saw bcm43 _work_ good on FC8
just make sure You browse the HCL, it often has proved itself that those few extra bucks are the most good spent ones.
;-)
best luck, and do provide feedback of outcome :-).