I've been wanting to print a custom case for my phone for awhile now and finally decided to go for it. I'm a huge WordPress fan so this speaks to my inner-geek. Using the Sketchup file at http://www.instructables.com/id/How-to-create-your-own-3D-Printed-iPhone-Case-from/ I added the logo and other design elements. For reference this is the iPhone 4 GSM model. My understanding is this should also fit the 4S GSM model (I hope so anyway, that's the phone I have) Doh! Turns out the CDMA version of the iPhone 4 is the one that matches the 4S. I've now added both the 4 (GSM) and 4S (which is also CDMA 4) as separate downloads.
The first time I printed this it ended up being too small so I scaled up 1.02 in RepG and that seems to fit pretty good. Depending on your printer settings and calibration your mileage definitely may vary. Good thing is it doesn't take very long to print if you get it wrong the first few times. I printed with zero shells to get the thin features of the Wordpress logo to come through well.