Based on Terry's recommendation, I bought some SANYO eneloop batteries. They cost $19.99 with free shipping (typical Amazon on orders over $25) which was a decent deal. These aren't your typical rechargeables. They're one of the new style that are supposed to hold their charges much longer during non-use. From the Amazon website:

Very slow self discharge maintains 85% residual capacity after 1 year of storage*and 70% residual capacity after 2 years of storage* Based on SANYO's simulation when stored at 20* C.

They showed up in a nice package, albeit a vacuum pack...one the packaging engineer's most evil inventions. Popped them out, into the Nikon SB-800, and voila...light! So far so good. I'll let you know how they hold up. So how do you pronounce the these anyways? Weird name