I just picked up 24 AA and 12 AAA rechargeable NiMH batteries for $29. The brand is Tenergy - I bought my first set of Tenergy batteries over 2 years ago expecting no-name korean junk. Anyway, turns out over two years of heavy use (weddings, photoshoots, sports, portrait stations, etc) they're still going strong and easily get 250-350 flashes in my 580 EX and SB24 speedlites. This vendor is the same vendor I purchased my first set from back in '06.

Link is here: http://dealnews.com/lw/artclick.html?2,244763,789363

Use the coupon code "dealnews" during checkout to save some dough

I have no affiliation with any vendor or 3rd party involved in this deal, just wanted to pass on the savings to any fellow FM'ers in need.