My phone takes pretty good pictures, but I find the quality slips when I can't keep it stable. This mount allows me to clip the phone onto my Gorillapod, giving me the stability I need. Being able to gorilla my phone to a post is also pretty neat.
I'm particularly happy with how the insert clip turned out. This mount will slide in and lock in place, just like the native part. (I've also broken the clip out into it's own scad in case you'd like to design your own Gorillapod-compatible thing.)
The included stl is for the Samsung Galaxy S (my phone,) but this is a parametric model, so you can change dimensions to suit your needs. If you leave a comment with your phone and dimensions that worked, I'll put up an STL so that future users won't need to muck with the scad.
UPDATE: I pulled the iphone4 dimensions off the apple website and added an stl because, you know, the iphone is popular. Please let me know if it works
Because it's being printed on its side, the clip may need a little x-acto work on the bottom edge, especially on the rounded corner. After that, you should get a nice snug fit that's easy to remove.