Question: Is there any way to coax Gmail into pushing new-mail notifications into my Linux machine, without using a full-on graphical mail client like Thunderbird?

**edit**: Thanks for all the responses, but (unless I'm mistaken) these applications all *poll*, none of them receive notifications *pushed* from GMail.

Also, I'd prefer a console-based program, as this will be running on a headless server.

Answer: 
[Mail Notification](http://www.nongnu.org/mailnotify/) supports Gmail. It can check multiple accounts simultaneously so you can also use it to notify you of new mail in Evolution, Thunderbird or IMAP and POP accounts.
Gmail doesn't push. You can receive an atom feed:  

<http://code.google.com/apis/gdata/faq.html#GmailAtomFeed>