Tirerack.com sells a pressure monitoring system that mounts the display on your dash and lets you keep track of all 4 tires. Kinda neat, and if you don't have a spare, might come in handy. I usually only take my spare when I go on trips, or I'll put in a can of fix-a-flat (it sucks and is flammable, but it does work decent) of course most repair shops won't repair a tire if you have used fix-a-flat and it will also void most tire warranties.
Chris, I'd like to see some pics of the brake upgrade. How hard was the install? I might do this soon since I now have 17's on my black bird, and the brakes are almost useless at high speed. Scary, a 4000 lb car going 75 mph needing to stop and having your foot to the floor on the pedal and barely slowing it down. I do have good rotors, new calipers, and recent carbon metallic pads too, so I now know even when properly equipped how poorly the brakes work on these machines. I think I can justify this as more of a safety thing than a performance mod, plus it looks cool I bet with the red brake calipers showing through the wheel, especially when driving and you can see that behind the moving spokes.