http://www.tirerack.com/tires/accessories/smartire2.jsp

I plan on replacing the toyos soon. really, over the life of the car, this would save money. (I would use the optional remote display) and of course the safety. And when your blasting along at 90+ on a desolate TX highway on a 115 degree day, it might be nice to know the temp.

btw, I hear that after the Explorer/Firestone fiasco, that pressure monitoring is mandatory in 2004. I think the Toyota Sienna has it (and of course the M5 and few other pricey cars).