If you login to your Google Webmaster Tools account, you may be prompted to add more sites to your account.

When I logged in this morning, I saw:

This was followed by a list of domains and then two buttons:

Add selected sitesAlways add

Here is a picture:

I should note that many of these were the non-www equivalent of sites I have already added to my Google Webmaster Tools sites list. It is best practice to add both the www and non www.

Forum discussion at WebmasterWorld.