I have Eclipse (Indigo Service Release 1, Build id: 20110916-0149) running on Win XP.
I\'ve added https://dl-ssl.google.com/android/eclipse/ and installed 4 plugins
I have Ubuntu , to make story short, I tried every advice here, nothing helped (reinstall, ADT removal- adding, run as sudo, deleting .eclipse folder etc). The cause of problem was running eclipse updates.
So, I downloaded ADT bundle as zip - adt-bundle-linux-x86_64-20130729 unpacked it, run eclipse inside it, used existing workplace, and it worked, 'android' option appeared in Preferences. However, there is no longer 'eclipse' splash logo at start-up, it's now called Android Developer Tools Build: v22.0.5-757759