I'm not sure how hot this deal is, but it seemed like a pretty good deal to me so I picked one up for myself.
http://www.samsclub.com/shopping/navigate.do?dest=5&item_nbr=292014&landing=292014
The Nyko Ultimate Kit for the XBox 360 includes:
4 rechargable NiMH battery packs
1 charging...
Halo 3 Collector's Edition (Xbox 360) is 47.82 at Walmart (B&M if you can find it, or online).
Stumbled upon this little gem accidentally and couldn't resist ordering it. I've held out on buying it for this long, but I've finally given in...