I have been using MMS to send emails to people since before I had a BB. If you use MMS and enter the email address instead of a mobile number it will become an email. I have AT&T with an unlimited text plan but no data plan so I don't use actual email. You can also recieve email as an MMS if you know your mobile email addy. For example... sending an email to
will send it to the mobile number selected as an MMS message. I also have an email address that forwards to my mobile addy and I can get emails that way. Now obviously these will be plain jane text emails and not html, nor can you view attachments or images, but if you want your friends to send simple emails you can do it this way.