just a quick review: http://www.peakeresearch.com/srstool.htm
i got this thing for my airbag light that has been on since forever because i messed around with the seat connectors without disconnecting the battery (doh). i finally had to fix it because i had a safety inspection coming up.
i'd say the price is reasonable considering what you get. you can scan for SRS system faults (comes with a book with all the codes) which in itself would be a $100 trip to the dealer. it will also reset the light if you want. and if you have friends, you can charge them to reset their lights too. just kidding.
so i reset the light. naturally the light stayed off because the problem had long since been rectified (not erectified or rectumfied).
i grade this product an A for ease of use, functionality, and FAST delivery. it even comes in its own nifty carrying case. disclaimer: i have no affiliation with peake research