I finally managed to borrow a BU-353 USB GPS receiver and added my very first roads to OSM. Here's my complete workflow:

1) gpsd -d ntrip://lindi:$PASSWORD@www.euref-ip.net:80/METS0 -f /dev/ttyUSB0 -N -n -D 1

2) echo rw | nc 2947 > a.dump

3) gpsbabel -i nmea -f a.dump -o gpx -F a.gpx

4) open a.gpx in josm, edit map, upload

Any idea how I could I apply DGPS corrections as a post-processing step? I don't always have access to internet.

Now that JOSM no longer depends on MinML2 ( http://josm.eigenheimstrasse.de/ticket/174 ) and icedtea ( http://icedtea.classpath.org/ ) builds on debian unstable I can finally edit OSM without having to touch any proprietary software. Hurray!

If you have debian unstable and are willing to experiment (I recommend a chroot) you can try the following:

1) Add "deb-src http://lindi.iki.fi/lindi/debian destructive main" to sources.list
2) sudo apt-get update
3) sudo apt-get build-dep icedtea1.3
4) fakeroot apt-get --build source icedtea1.3
5) sudo dpkg -i icedtea1.3*.deb
6) sudo update-alternatives --config java and choose /usr/lib/icedtea1.3/bin/java
7) sudo update-alternatives --config javac and choose /usr/lib/icedtea1.3/bin/javac

Again, this is totally experimental, use your own risk etc. I hope icedtea (and josm too!) will enter official debian soon.

If you are paranoid you want to check that the included icedtea-1.3.tar.gz and openjdk-7-ea-src-b18-16_aug_2007.zip match what upstream distributes and then read through debian/rules (it's fortunately not too long). Finally, the sources should be signed with my GPG key AA6D106B that is also signed by some of my friends: http://webware.lysator.liu.se/jc/wotsap/wots/latest/paths/0x135EA668-0xAA6D106B.png