echo "deb http://www.e-oss.net/ubuntu/gutsy/ ./" | sudo tee -a /etc/apt/sources.list
sudo apt-get update
sudo apt-get install pytrainer
sudo apt-get install python-gnome2-extras

To get the Garmin kernel driver working in user space, make an udev rule in /etc/udev/rules.d/51-garmin.rules with this content

SYSFS{idVendor}=="091e", SYSFS{idProduct}=="0003", MODE="666"

Pytrainer is made to use path like /dev/ttyUSBX to connect to the Garmin watch. I believe the right way is to use Garmin usb driver directly, hence usb: in the config. Therefore you have to open /usr/share/pytrainer/plugins/garmin-hr/main.py and change

if not os.path.exists(options.device):

to

if (not os.path.exists(options.device) and not options.device == "usb:"):

In Tools -> GPS Device Plugins -> Garmin* ->Preferences change device to [usb:] and status to [Enable].

Thats it, have fun :)

Updated: 11 January 2009:
- Quotes in code-blocks is now "copy/paste enabled"
- Pauls comment from December 31st, 2008 at 14:22 added to the text

Griseløbet er iøvrigt et rigtig godt løb, som varmt kan anbefalse. Se Snik atletiks hjemmeside for info. Snik er også med i BTs halvmarathon som samtidig er DM, så det jo bare med at komme afsted :)