The Zimbra Collaboration Suite is full of clever tricks. The latest version (4.0) of this online e-mail, calendar, and address book system adds the ability to easily access your account from certain cell phones.
The Zimbra suite includes both the online client (which displays your e-mail messages, appointments, and contacts) and the server that client runs on. You can download and run the software for free if you like. (Zimbra charges US$25 per mailbox per year for technical support and extras like mobile access, with a minimum of 25 mailboxes.)
Perhaps the most impressive new feature in version 4.0 is its simple mobile setup--if you have the right phone (any Treo, the Symbian-based Nokia E61, or any phone that runs Windows Mobile OS 5 or above). I plugged my user name, password, and server information into a Treo 700p, and a couple minutes later I was viewing my messages, calendar, and contacts.
Despite the suite's sometimes rough edges, Zimbra offers an innovative and inexpensive e-mail alternative.