Today I wanted to try the Android SDK on my Ubuntu Karmic Koala, so I followed the instructions in the following URL.
I thought that an IDE would be useful so I installed Eclipse 3.5.1 and tried to install the Android Development Tools, or ADT. However, an error "org.eclipse.gef 0.0.0 required" (or something like that) appeared.
After googling for a while, I found a URL for the GEF SDK, which is Eclipse's Graphic Editing Framework, as the following URL.
So I added this update into Eclipse by
After installing GEF SDK, return to installation of ADT. You should be able to install it now.