I've been in communications with a trooper on FISD and he's come up with a unique alternative to the iCOMM, ROMFX, and some of the smartphone apps. It runs on the teensy system which is a type of microcomputer. What I like about this system over some of the others is how easy it is to customize. I built the entire thing for less than $100 and it takes up less space than an iComm. The project can be seen at TKTalkie.com
Here's how I had mine setup. I've made a few changes to other electronics since then though.