Well, for a phone it ain't really that amazing, but in the this (at least yet a while) small world called OpenMoko this is actually a break through for me! I've just made the first call from my Neo1973-phone with OpenMoko. Not through the Dialer or anything that fancy, just by executing AT-commands from the terminal.
I roughly followed the guide on the wiki page, but here's explicitely what I done.
Open two terminals (for example through USB-networking and SSH to the phone).
In the first terminal execute these commands:
/etc/init.d/gsmd stop echo "1" > /sys/bus/platform/devices/gta01-pm-gsm.0/power_on chown uucp.uucp /dev/ttySAC0 cu -l /dev/ttySAC0
And in the second terminal execute these commands:
mkdir -p /usr/spool/uucp chown uucp.uucp /usr/spool/uucp stty -F /dev/ttySAC0 crtscts
Now go back to the first terminal and play with AT-commands; I made an outgoing call as follows (responses are included):
ATE1 OK AT+CFUN=1 ERROR AT+CPIN="x" OK AT+COPS OK ATDy
where x is the PIN and y is the phone number (for Danes: I only used the eight digits - no leading zero or anything fancy). Please notice that there is no space whatsoever between ATD and the actual number.

November 19th, 2007 at 15:31 (UTC)
I don't know what's happening today, but something's really good! I've just managed to use libgsmd-tool, too, with the following commands and accompanying log (after exiting the cu-session):
root@fic-gta01:~$ /etc/init.d/gsmd start
Starting GSM daemon: gsmd.
root@fic-gta01:~$ libgsmd-tool -m shell
libgsm-tool - (C) 2006 by Harald Welte
This program is Free Software and has ABSOLUTELY NO WARRANTY
O
# Power-On
EVENT: PIN request (type='SIM PIN') Please enter SIM PIN: x
sending pin='x', newpin=''
r
# Register
EVENT: Netreg searching for network
EVENT: Signal Quality: 23
EVENT: Netreg registered (home network) LocationAreaCode = 0x001E CellID = 0x7D34
EVENT: Netreg registered (home network) LocationAreaCode = 0x001E CellID = 0x8FE0
EVENT: Netreg registered (home network) LocationAreaCode = 0x001E CellID = 0x7D34
EVENT: Signal Quality: 27
Dy
# Dial y
EVENT: Outgoing Call Progress: UNKNOWN
EVENT: Outgoing Call Progress: PROCEED
EVENT: Outgoing Call Progress: SYNC
EVENT: Outgoing Call Progress: ALERT
EVENT: Outgoing Call Progress: SYNC
EVENT: Outgoing Call Progress: PROGRESS
EVENT: Outgoing Call Progress: CONNECTED
EVENT: Outgoing call colp = ""
RSTR=`OK'
EVENT: Outgoing Call Progress: SYNC
EVENT: Signal Quality: 23
where x and y is the same as in the post.
November 19th, 2007 at 15:41 (UTC)
While performing these calls I've got some odd messages on my answering machine - the first (when using cu) was a repeating bip-silence-sequence, whereas with the libgsmd-tool it was only silence. Maybe I didn't terminate the calls properly or something similar.
By the way: I'm using a newly compiled u-boot, kernel and rootfs - actually it's still hot! Just for info.
November 19th, 2007 at 16:06 (UTC)
And of course it also works from the Dialer! WHAT A FANTASTIC DAY!