My set-up is my N900 using UMTS (or WiFi if I'm at home) connecting to my Asterisk box which handles call routing and voicemail, and which connects to the plain-old-telephone-system via Vitelity. Alternatively, you could skip running your own Asterisk server and just connect to Vitelity directly (or run Asterisk on the N900).

I believe Android's Gingerbread release also supports SIP, but I don't have direct experience with that. Either way, I use SIP over 3G and WiFi quite a bit since it's significantly cheaper than when I'm on the mobile voice network.

It's not that I don't believe you--there are lots of phone and network combinations--but this isn't a necessary EDGE limitation. Take a look at the GRPS classes (specifically class A or class B) and DTM.

Even when I was stuck on GPRS and later EDGE using a class B phone, most have an option to ignore incoming calls if you're using data. If you don't have that option checked, your data connection will be suspended during an incoming call. I've had a number of DUN sessions suspended because of incoming calls--and even had SSH sessions resume beautifully if I kept them short enough. That goes back to the first Bluetooth and GPRS enabled phone I owned back in 2003 and through several models I've owned since.

There are three possible meanings to the phrase

.

a) A system has (more properly a "largish" subset of systems running the Ubuntu distribution have) stability problems.

b) While the machines themselves are stable, there could be significant changes in the distribution over a relatively short time.

c) The distribution has a psychosis.

I'll let others approach a and c. As for b, the distribution does have stability issues as compared to most mainstream distributions, let alone Debian-stable. I've yet to go through an Ubuntu update without having things break requiring some moderate digging around.

Some obvious things that I wouldn't have expected to happen in Debian:

Ubuntu pushed new Nvidia drivers at nigh the last moment, as happend with Jaunty. The drivers had some stability bug and the fix on launch day was to revert to an older version from the beta. Debian would never release binary-drivers with it's distribution.

Ubuntu changed configuration systems between Jaunty, Karmic, and Lucid--specifically those configuring input in X. The Synaptics touchpad on my MacBook worked fine in Jaunty. I've not gotten it to work right since but looking at the configuration files for each system shows the radically different configuration systems, and the update process obviously didn't do the Right Thing during the update since it broke. Debian would never have three named releases within a calendar year.

My girlfriend managed to update from Karmic to Lucid by herself. I had told her that it was ok to update packages as they became available, but hadn't realized how easy it would be for her to actually update the entire system to a new release. Her Eee PC's wireless networking and ACPI triggers broke forcing me to fix things that had just been working manually. Some of these came back with a reboot, for others I needed to find the "new" packages in Lucid, for others some manual tweaking, and apparently some of the buttons aren't working "right" still. I never would have had a girlfriend running Debian.

http://broadbandusa.sc.egov.usda.gov/files/BTOP%20Peer%20Reviewer%20Letter%207-6%20v2.pdf

I followed the link in the article to the paper that supposedly requested reviewers, and I got a 404.

A cursory scan at the Federal Register notice (Vol. 74 No. 125; Wed July 1 2009) hasn't have anything stick out either as far as volunteers.