Where to get cheap embedded system

Hi,20%

I'd like to build software for an embedded system.  I am considering =
using an I-pod (or similar) device or possibly a printer, because these =
have native drive options, and some printers have networks already built =
in.    Anyone else have any better ideas.   I could always hack an X-Box =
I suppose, but I'd like to go even cheaper than that.

While I intend on designing some serious systems later, something up =
front would be nice just for some practice.  I'd like to remaster an =
I-Pod Linux for decrypting and encrypting PGP encoded messages, without =
losing the ability to play MP3's if possible!  20%

I was thinking the printer could be an excellent webserver for some VERY =
low volume hosting.  Of course, I'd still like to maintain printability =
if possible - although I don't know what size the firmware in these =
units is.    I'm not even sure printer firmware is upradeable :(

Set me off on the right track.   I'm thinking networking, existing =
platforms, some way to input (interfacing with buttons, Serial port . . =
I dunno)  Some ideas are Cell phone, digital camera, Palm Pilot (or =
similar) 20%

First project will be a security system, monitoring n/o n/c channels and =
notifying an existing computer network if something changes or is =
unexpected.  20%

--20%
"When you have to choose between a first-rate company with a second-rate =
product and a second-rate company with a first-rate product, it's never =
an ideal choice. " -Ed (www.overclockers.com)