My eclipse updated ADT to 20, which I believe sucks, and I want do get 18 back. But can\'t find where to download it from.
In here https://dl-ssl.google.com/android/
Download this file:
http://dl.google.com/android/ADT-18.0.0.zip
Then when going to install new software, click 'Add...' followed by 'Archive...' and then select the folder.
You can get it from
http://dl.google.com/android/ADT-18.0.0.zip
To get any other version, just replace 18 with another version. Hope this helps!