Ac Adapter Instead Of 2 Aaa Batteries

[+frefel]

I use a Visor PDA for my paperless caching. The unit normally uses 2 AAA batteries in a conservative fashion but I also have a Thinmodem attached to it and when I use that it sucks juice like there is no tomorrow. Since there is an amazing amount of knowledge on this forum, since I'm almost always near a plug when I use the modem and since I've been unable to find anything via "search" on the Web, I'd like to query the membership if it knows of a device that would draw AC power and convert it to appropriate DC equal to 2 AAA batts and be easy to connect to and disconnect from the PDA?

Thanks for any ideas.