I am an iOS developer (iMade iWhiteBoard) who is a jailbreak-evangelist, and I've done 20+ devices for others. I'm always interested in learning more about the security of iOS and laughing when Apple fails at such task. I'm proficient in C/Objective C and I'm looking into Arm assembly code.
Currently, I have a 16GB iPhone 4, an 8GB iPhone Original (good for testing on 3.x and slow procs) and an iPad 3G (16GB).
You can find me on Twitter
A note to developers out there -- Private Api's are your friend... and so is Mobile Substrate ;)