A new SLR adapter for iPhones 3 and 4 is out from online photography shop Photojojo.
The kit includes a case for your iPhone, UV filter and lens adapter for either Canon or Nikon lenses. $249 for the iPhone 4 edition and $190 for iPhone 3/3GS.
There have been several attempts at iPhone SLR adapters in the past, but this seems to be the first mass-produced attempt. The new iOS 5 "volume-up as shutter release" feature should work together nicely with the SLR rig.
Jeremy Salvador previously designed a iPhone SLR mount, but wasn't able to successfully commercialize the product. He comments on PhotoJojo's attempt:
Sure the case and adapter combo is ridiculously sized – but what other device can take a photo, edit it on the fly, and share it on the internet? The purists can scoff all they want at this one. Score one for the iPhone hackers.
Now there are still going to be some draw backs.
At $200+ it's certainly not for everyone, but for photographers with lots of glass kicking around, there are worse ways to spend the money -- if it works.