As we’ve been counting down to this iPhone morn, our inboxes have been stuffed with applications and accessories geared for the year’s biggest phone phenom. Most are just addons that could likely fit on any phone, and are using the launch to goose sales, but some are a little more interesting. There’s even a new search site for iPhone applications at AddFone. Here’s a few we’ve been hearing about (we haven’t tested any of these, so be forewarned):

1). Social apps: iPling, a San Francisco based startup founded in January 2007 says they have a location-based social networking service optimized for the iPhone. There’s a lot of LBS mobile apps out there, and this one’s focus on the theme of “openness” is way too vague.

2). Cases: If you were sick of people selling every type of iPod cover, well, of course iPhone needs its own cutesy cases too. Wrappers says it’s giving away 50 iPhone covers for the sleep-outside-the-store crowd to test out and review.

3). Corporate email: Mobile email company Visto says it will offer corporate push email for iPhone users, available for current and legacy versions of both Microsoft Exchange and IBM Lotus Domino. The service will be launched in the third quarter of 2007.

4). Headphones: Plantronic’s Altec Lansing division is selling an ‘Upgrader Series’ of headphones, with a microphone and an adapter for the iPhone as well as other cell phones. Available August 2007.

5). Online storage: Seefile.com announced a hosted online storage service for iPhone users, which will go live later today. It says 5G for free.