I don't know if this has been posted or not, but Amazon has the Targus TG-BGXTI Battery Grip for the XT and the XTI for cheap right now. I ordered one this morning and using the promo code below it is being shipped to my door for $24.32. Couldn't pass it up for the price.
Promo Code: TARGUSO9
There is also one available for the Nikon D40/D40x/D60 for a few dollars more. Use the same promo code.