Not everyone is waiting for the software developer's kit to build applications for the iPhone. A small Chicago-area company called Genius & Tequila has already gone to market with MailCurve, a "refined" e-mail service created just for the iPhone.

MailCurve uses a proprietary filtering technique that allows users determine exactly which senders' messages are copied through to the iPhone when they check any or all of their e-mail accounts. All they need to do is have copies of their e-mails sent to their MailCurve address, and from there they can manage all incoming traffic directly on the iPhone.

"Mobile e-mail is usually extended, secondary e-mail of some kind, so it's a great opportunity to make it your best, refined e'mail," said MailCurve creator Brian McAlpin. "Instead of trying to determine what types of mail to reject, you choose the only senders allowed to even reach your iPhone."

The company is offering a free two-week trial, after which the app carries a $34-a-year subscription fee. MailCurve is a Web-based service, so there's no client to download to the iPhone. Click here to check out a demo.