If you try to start Eclipse opening wizard for Git and have the following problem (Indigo version, around 18/2/2012):
The selected wizard could not be started. Plug-in "org.eclipse.egit.ui" was unable to instantiate class "org.eclipse.egit.ui.internal.repository.NewRepositoryWizard"
Then just add as a software source the following:
and update. It will fix the problem. I found that lying somewhere in a forum, but I lost lots of time trying to pin it down.