The standard Tomboy that comes with Jaunty will not sync to WebDAV. This page details a fix.
Copy and paste into a terminal:
cd ~ mkdir tmp-tomboy-webdav cd tmp-tomboy-webdav sudo apt-get install --no-install-recommends pkg-config tomboy wget libgtk2.0-dev libneon27-dev libfuse-dev wget http://noedler.de/projekte/wdfs/wdfs-1.4.2.tar.gz tar -xzf wdfs-1.4.2.tar.gz cd wdfs-1.4.2 ./configure make sudo make install cd ..
For AMD64, copy and paste:
wget https://edge.launchpad.net/~brywilharris/+archive/ppa/+build/949140/+files/tomboy_0.14.0-0ubuntu1-1bh_amd64.deb sudo dpkg -i tomboy_0.14.0-0ubuntu1-1bh_amd64.deb cd .. rm -rf tmp-tomboy-webdav
For i386, copy and paste::
wget https://edge.launchpad.net/~brywilharris/+archive/ppa/+build/949141/+files/tomboy_0.14.0-0ubuntu1-1bh_i386.deb sudo dpkg -i tomboy_0.14.0-0ubuntu1-1bh_i386.deb cd .. rm -rf tmp-tomboy-webdav
Run Tomboy and, in the Search All Notes window, select Edit > Preferences from the menu. Choose the Synchronisation tab, then the WebDAV service from the dropbox, and key in the necessary details for your WebDAV account. You are advised to press the Advanced button and check those settings before you Save and Close the Preferences dialogue.
To synchronise, got to the Search All Notes window and select Tools > Synchronise from the menu.
Tomboy uses WDFS for WebDAV syncing, not FuseDAV. There is no package in Jaunty for WDFS so it must be compiled from source.
Tomboy is installed twice here: once from the standard repository to make sure you get the menu shortcuts and icons, and again as a patched version to work with kernels that have FUSE compiled in, as the Tomboy shipped with Jaunty tries to load a FUSE kernel module when syncing. The other packages are needed to compile WDFS and download the sources.
Many thanks to Bryan at Launchpad who made the patched Tomboy packages.