[rocqua]

Look into EAP-SIM and EAP-AKA for some concrete examples.

I believe mobile payment also uses the SIM card, but I'm not sure.

For a more general overview see https://en.wikipedia.org/wiki/Universal_integrated_circuit_c....

There is apparently a toolkit to design applications to run on the SIM https://en.wikipedia.org/wiki/USIM_Application_Toolkit

I don't know of any other implementations. An SSH auth module using SIM would be pretty cool.