The TIP102 has a Vceo "collector to emitter breakdown voltage" of 100 VDC as aposed to 60 Volts for the TIP120.  thats pretty much the only major difference.  switching anything under 40 Volts, i would just use what ever you find easiest to get your hands on.

David

I haven't received my first Arduino board yet, "still waiting for that little package from SparkFun", but from what I see on all the pictures, it looks like they all have the 6 pin ISP connector on them.   You'll need Atmel's in circuit programmer or a similar clone in order to use the Adurino board as a programming platform for blank chips.

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=ATAVRISP2-ND

David.

Will this work for you?  you can buy it for $49.00.  I have two of them at work, no one has written I2C sniffer code for it that I know of yet but it works for many common tasks in the lab.

the PICkit Serial Analyzer from Microchip

http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en028600

David