I have been a fan of tomboy since i used GNOME for the first time, its a handy tool for quick notes such as saving something while you are on the phone or day to day task listing. Problem with tomboy is its a ‘little’ greedy on resources. Lucky us, someone wrote a non-mono/gtk tomboy alternate called gnote. I have shifted to gnote since i came to know about it. Its just like tomboy, or should i say its tomboy but faster.
You can install gnote by:
aptitude install gnote
apt-get install gnote
OR ofcourse you have adept/synaptic/add-remove/software central as a GUI alternate.