Gmail Lets You Set From: Header
Gmail now lets you configure the From: header of the mails you send. This is great news if your “official” mail address is something other than “…@gmail.com” and you only use Gmail as your back end for storing, reading and writing mails. With the proper From: header (as opposed to the Reply-To: header, which has always been configurable), people won’t accidentally add your Gmail address to their address books. This in turn means that it is easier to switch to a different mail system if you should become unsatisfied with Gmail.
This is a pretty generous feature from Google, considering that they are really removing a lot of lock-in into their system.
Updated: Added screen shot:
Update: As Paul points out in the comments below, Your Milage May Vary depending on the user interface language set in Gmail. Its seems, though, that you can switch to English (US), add a new “From:” address, switch back to your favorite language and still use the new address.