If you're using Ubuntu 9.04 (or still in 8.10) chances are that you are still running Mono. No, it's not mononucleosis but you can think of it as a disease. I would say that you computer is infected with mono. What is mono and why you should remove it? Well, start here but sooner or later it all comes to: do you trust Microsoft? I don't, I'm not going to risk and I don't even need Mono so... Bye bye Mono! This is how I did it.
F-Spot, Tomboy and Gnome Do are gone. And I only miss Gnome Do.
gThumb and Launchy are in.
I'm running a Mono free computer and I'm happier this way ;)
Just read this post :) Funny, pretty much the same conclusion :)