We have the Archive and Report Spam buttons inside GMail. Wouldn’t it be great if Google had an Unsubscribe button too for those emails that come in via Newsletters? Much better than having to go into each email and finding and reading their method of unsubscribing from their mailing lists. Perhaps if Google and Yahoo! and Hotmail came up with a common standard like nofollow it would get a wider adoption?
In return GMail might more strongly ensure these newsletters don’t get marked as spam.