Small embedded computer board? (SLD PXA 255 DIMM)

[Thomas Shaddack]

http://www.hw-server.com/test/sld_hws.html
Take a look at the DIMM modules.

Looks like a good candidate for a battery-powered portable VoIP/GSM
encrypted cellphone. Add a GPRS modem or a cellphone (or, for landline
version, a modem), a small display/keyboard, and eg. SpeakFreely with
suitable session key handshake, stir, serve warm.

Does it look like an usable way to have open and reasonably cheap
($160+cellphone+some parts around) portable secure telephone platform?
Does anybody here have any experience with embedded computer hardware,
who could confirm or deny this kind of hardware as bearing hope for this
application?