Need another ac adapter? This offer expires Dec. 11. (BTW, I have no affiliation with the people selling these.)
http://dealmac.com/deals/Refurbished-i-Book-Power-Book-AC-Adapter-for-25/102807.html
http://dealmac.com/deals/Refurbished-i-Book-Power-Book-AC-Adapter-for-25/102807.html