We do it when indicated; we have a set of criteria for indicating IAP monitoring. Every trauma gets it, some abdo surgeries and some other stuff that I can't remember - it doesn't happen all that often. I had a guy with a nasty intra-abdominal sepsis the other night, and the medicos declined IAP monitoring.
I dunno, I'm still pretty new to ICU (6 months in). Anyway, we have our own jerry-rigged kits with a transducer, sterile tubing, a connector, 500mL NS, 50ml syringe, and a three-way tap. Sounds pretty similar to the one mentioned earlier. There are commercial kits available, but they are quite expensive, so we make our own.