lattesurf, I was toying with the idea of making one when I saw this. A few of the web pages I found that showed how to build them claimed that the AA versions returned 2.5 times more power than the 9V versions.
Someone had also posted a comment that you should not try to board a plane with your homemade battery pack as it could cause you long delays and get you a cavity search :shock:
Sounds like good advice to me.
Glad to see that your exams are over, time for some R&R
Has your new player arrived?