I have upgraded my ubuntu box from Feisty Fawn to Hardy Heron.

I backed-up my home folder before that and dumped it to the home of newly installed Ubuntu 8.04.

Now, my sticky notes were gone…

After some googling i found out that it is somewhere inside /home/user/.gnome

In my case I found it inside /home/user/.gnome2

using

gedit stickynote_applet

in terminal

I was able to view my old sticky notes… 😀

you can also try

locate stickynote

in terminal to locate it