I've recently started playing around with git and found out the power of gitk. Gitk is a small tool built using tcl/tk that helps the user visualize the changes he's done in a graphical, easy to follow manner. By default Ubuntu 10.10 ships with tk8.4 installed by default and that makes gitk look really ugly, as tk8.4 doesn't support antialiased fonts. To fix this problem simply install tk8.5 and make it default on your machine:
sudo apt-get install tk8.5 sudo update-alternatives --config wish # a list will show up and you need to type in the number that corresponds to tk8.5 (in my case was 3) then hit enter.
That's it. You can now reopen gitk and see the difference.