|Yo "Gimp",... what u think! ;-)|
Here are few of the main features...
*. A tool-bar which consists standard tools such as - eraser, cropping tool, freehand, Font selection, ellipses, etc.
*. Supports unlimited layers (+ full history undo).
*. Image effects (over 35 currently according to the developer) and enhancing tools.
*. Locked or Unlocked window support (workspace).
*. Zoom in Zoom out.
*. Re-size, scale... images.
*. Save in different formats, etc.
So, if you have installed Ubuntu 10.10 then you can install Pinta (using PPA) by issuing the below command in your Terminal
sudo add-apt-repository ppa:moonlight-team/pinta
sudo apt-get update
sudo aptitude install pinta
You can use this PPA to install it on Ubuntu 11.04 as well, but since it is still in beta, there could be some issues. But it is worth giving a try.