ProcrastiBlog

Interestingly, it can be done without losing your email, although it is not officially supported. Here's how it's done (with a hat tip to these guys over here):

1. In your old account, go to "Settings -> Forwarding and POP" and select "Enable POP for all mail".


2. In your new account, go to "Settings -> Accounts" and select "Add another account"


3. Enter your old email address and click "Next."


4. Enter the username and password for your old account. From the "POP Server" drop-down list choose "Other..." and type in "pop.googlemail.com".* Unselect "Leave a copy of retrieved message on the server."** You may also want to tag or archive the retrieved messages, but you can change these settings later.


5. Click "Add Account." If something goes wrong, fix it.


6. Now wait. The emails will come slowly and out of order, but they will come. They'll even have all the right timestamps and such. It took about 8 hours for approximately 800 messages to be loaded from my old Inbox. (Presumably, Google throttles the message transfer so that you don't interfere with everybody else's everyday Gmailing.)


7. When all of the emails have transferred, you can go back, turn off POP, and enable regular forwarding. This will be much faster, in general.

Transferring your contacts is easy. The Export/Import links are in the upper right corner of the Contacts page. There doesn't seem to be any way to get somebody into your Quick Contacts box without sending them an email.

Note: Changing your Gmail account will screw up all your other Google Account stuff. Like your Blogger account. D'oh. [UPDATE: No really, this is probably the worst "feature" of Google Accounts. If I log into Blogger, I log out of Gmail and vice versa. I can probably somehow get around this by inviting the new me to join this blog...] [UPDATE 2: As you may notice in the Contributers bar to the right, there are now two of me contributing to this iblog. This is annoying.] [UPDATE 3: This was a known bug with "New Blogger" that has since been fixed.]

* This is part of the trick. The pre-fab list of gmail.com servers won't let you suck in all of your mail, but this undocumented googlemail.com server will.

** This sounds frightening, so some clarification: Gmail won't let you leave this selected; they've got the POP server set up to complain if you do. However—and this is weird—your mail won't actually be deleted from your old account. This setting doesn't mean what it says, somehow.