I was just looking around the other day for a keychain light for my wife and happened across the Nitecore EZ AA (w/XP-E R2) and while I don't have one, I'd suggest it is a good candidate because it has two brightness modes and a simple interface.

Turn and it comes onto low (10 lumens), some more and it goes into high (145 lumens). Run time in low is about 20 hours (independent run time tests seem to suggest this is close) and is about an hour in high.

10 lumens is a good amount for task lighting, and 145 is quite bright. Seems like quite a flexible little light.

FWIW, I suspect Haertig may be right in that an AA light might have trouble fitting in an Altoids tin. The Fenix E01 might be a good AAA choice and comes in colors (10 lumens for ~10hrs).

-john