Haha i know what you mean.
I had a quick search on gimp and found this, i hope it helps.
2.Open up that image.
3.Add an Alpha Channel by clicking Layer -> Transparency -> Add Alpha channel.
4.Launch the Fuzzy Select Tool by pressing the m key.
5.Click on the background.
6.Press the Delete key.
7.Save it as a .png file, as that supports transparency.