Smart phones and their associated data services can be costly, especially if you choose to receive all your email on your phone. So here's a cheap way to get some email on your phone via Mail.app
- Discover your cell phone's email address equivalent. For instance, 1234567890@mycingular.net.
- In Mail.app -> Preferences, create a rule that dictates what sorts of messages you'd like forwarded -- such as members of an Address Book group, or a high priority message, etc.
- Set the Rule to 'Forward Message' to your cell phone's email address equivalent.
- Make the Rule active whenever you are away from your computer.
You carrier's data charges may apply, but could be worth it when you get that important message in time.