Humm, just got back from my expidition to Menards, cute little Osram bulbs, 12v 20w with a glass cover, just the thing to keep dirt and moisture out. 38* beam, 35mm dia, PN#44890 WFL, 12v.
Less than 4 bucks.
But my real find was a battery pack, Schumacher Mity Mite, 12amp/hr. $11. out the door! Built in 120v charger and 12vdc lighter socker and big battery clips.
Really the only drawback is its almost 20 lbs.

BTW: found this neat item on ebay, anybody know about them?
http://cgi.ebay.com/ws/eBayISAPI.dll...category=22684