Hi Wes,
You have a couple of choices, you cann get going very quickly with the DS2250 from Dallas, which has a DS5000 mounted on a tiny SIMM card.You need a Maxim MAX 202 for a serial port, and a picogate inverter.

The catch is that the Dallas 5000 is only an 8031, and as such it lacks Timer 2 which is a real pain. Timer 2 has lots of useful options !

Or look at Atmel and the 89S53 family.
Or Temic (which is Atmel) (which is now ST I think.

The Temic parts program through their serial ports too so I'm told.

There are copious app notes on the Atmel website.

Phillips also have a great line in ISP microontrollers


Steve