I've been looking for many years for a good note-taking application. While still on Windows, I used (and paid for) ClipCache, which was perfect. I've not found anything that meets my needs as well, yet, in the FOSS world.
I used Basket for a long while, until an update lost all my stored notes! My efforts to restore them were futile. Now Basket is no longer being developed, or I would give it another try. A student proposed making Baskets and Notes shareable as a GSoC project, however, no mentor could be found. So I've given up hope there.
I also tried out TuxNotes for awhile, but again, my notes were lost in an upgrade. This is just not acceptable. This project seems to be totally gone, or maybe I am remembering the name of the app incorrectly.
Big windup for my decision to download and install Tomboy, with the announcement of TomDroid, which I can use on my phone too. I really hated to download all that gnome/ubuntu/mono stuff to support it, but oh, well! I do have an UbuntuOne account, whether it works natively on Kubuntu or not (it does not). Now my notes will be available to me *everywhere*, which is what I want. AND, I'll never lose my notes again!
Sad update: UbuntuOne didn't work in Maverick, and it still doesn't work in Natty. Not even the ugly Gnome version. Le sigh. https://bugs.launchpad.net/ubuntuone-client/+bug/369230