Gmail via Reader

You may be in an environment where you can get to a news reader, but you can't get to online e-mail. Gmail tries to make that easier, by allowing you to read new mail in your Gmail account via your news aggregator, such as Bloglines.

From Gmail Help Center:

How do I view Gmail messages with my aggregator?

You can view Gmail messages in your aggregator by subscribing to a new channel. Enter https://mail.google.com/gmail/feed/atom in the URL field, then submit your Gmail address and password.
Keep in mind that Gmail messages won't appear in your aggregator unless there are unread messages in your inbox.

updated 1/3/2006

Update: Bloglines and Google Reader do not appear to support this. It works fine with Onfolio as it prompts for ones userid and password.