So far, only the jailbreakers have been able to pair up a Bluetooth keyboard with their iPhone, but ION is working on a hardware solution -- they're showing off what's basically a dock at CES that has a full-size keyboard connected to it. Very interesting. Of course, it makes the iPhone a lot bigger (though their marketing says it's for travelers who want a little something less than a full laptop computer -- if only there was a device released to fill that need), but it's also battery-charged, so it'll recharge your handheld while allowing you to type out emails and messages on a full keyboard.
The price is supposed to be "slightly more than $100," and a release is set for the second quarter of 2010. If you've wanted to use a full-size keyboard with the iPhone but haven't gone for the jailbreak, we'll keep an eye on the release for you.