Openmoko
I have a Neo Freerunner. I got it to experiment with putting Linux and GPS together on a small handheld device. The fact that it happens to have a cellphone built in was not a factor.
It turns out that I am now using it as a phone and not using GPS right now at all. I still want to us the GPS but time and the other 14 GPS receivers that I have available all conspire against me.
I came by a $20 cellphone demo SIM card so I tested out its cellphone capabilities. I was able to test both GSM voice and GPRS data services for a month. I discovered my phone had the buzz problem and had it fixed in June.
Now I am using a pay-as-you-go T-Mobile SIM, and the Neo works great as a phone.
I am using a 4GB Sandisk MicroSD card. To avoid known problems with GPS on the FreeRunner I use an external antenna when I play with the GPS.
Current distribution
In January 2009 I settled in on the QTopia image. Shortly thereafter, Trolltech stopped supporting it and it morphed into the community supported QTmoko image.
I guess technically I should say "QT Extended on Neo FreeRunner"
Basics
Shutdown - hold down power key.
Wake from suspend - tap power key.
Not so basic
Bring up a WiFi connection -
Using a bluetooth headset for phone calls
Using a bluetooth headphones with media player and phone calls
GPRS networking with TMobile
Works fine once you know the secrets: http://johnsu01.livejournal.com/232100.html?view=280228#t280228
It's a ppp connection so have the extra kernel modules installed. Make the /etc/ppp/ link to /var/run/resolv.conf so that names get resolved.
Other distributions that I tried
I have had so many distributions loaded, the poor thing must be very confused.
Openmoko says that the "way forward" is FSO but it's just a framework right now.
OM2008.12 - Crashed too often when I had it set up with a usable set of tools. Openmoko with OM2008.12
FSO - just a framework, not usable for anything except development. Illume
SHR - FSO + some extras - "S" is for stable but it's not done yet! Phone works. There was no "testing" rootfs so I used the "unstable" (it was the only choice!) Illume SHR
Android - Phone app crashes every 30 seconds. UI seems a bit lightweight. Seems like a toy to me.
QT Extended - very nice. Seems very solid and user interface is good. Could not find WiFi support. (Perhaps I just need extra package for wifi?)
FDOM - too much cruft, like the name says "Fat and Dirty", cluttered UI Tried it out last year around August.
Debian - planning on loading it tomorrow
Gentoo - have not tried it; hard to believe, huh?
My phone
ME 354651011662048
S/N 8A8603722
DATE CODE 20080621
GSM 850/1800/1900