You can do a lot of things with a jailbroken iPhone. It is even more of a hacker's toy than a rooted Android device. Compiling any GNU apps makes a jailbroken iPhone like any UNIX computer. E.G. You can compile Apache, MySQL, run PHP, Nexxus. nMap, with a few compile and make commands. You don't even need GUI apps anymore. Everything is in the command line. Install a SSH daemon, easy. Install Apache, easy. Install Samba, easy...
You turn it pretty much from a phone into a UNIX workstation. You can even install Debian and load Android on it.
I used a jailbroken iPhone with nMap and Python to nuke and generate BSODs on Windows 7 machines for fun like Trinity in the last Matrix film. This is why iPhone are still very popular with hackers. Wifi tethering, you don't need an app for it. A simple bash script does it for you since the very 1st gen jailbroken iPhone.
A rooted Android phone still has issues. E.G. in order to run any real root POSIX stuff, you need BusyBox. I still haven't seen an easy way to compile GNU apps on Android without having some issues. I have seen any NON dalvik GUI apps that do not require an apk to run. E.G. , you can't run ./zenmap or ./wireshark from the commandline on a rooted Android.