Google has turned on POP access to Gmail accounts:
They’re rolling it out in phases, so it’s not available on all accounts. They also require SSL/TLS encryption for all connections, and use non-standard POP and SMTP port numbers.
Go here for all the details, including “What about IMAP?” (short answer: coming soon) and details for configuring just about any mail client out there (Outlook, Eudora, Thunderbird, etc.).
What does this have to do with mobile devices? It means that you can now send and receive Gmail on your Smartphone, Treo, or Pocket PC Phone Edition. Just configure your mail client to access pop.gmail.com/smtp.gmail.com with the proper encryption settings and port numbers, and you’re set.
I’ll try this out on a few devices, and let you know how it goes.