What kind of spider is this? (one pic, but dialup warning)

[Orrex]

Legs included, it appeared to be about the size of a half-dollar. I live in western PA, and we found this under a flower pot on our front lawn.

All I know about spiders is that the radioactive ones can turn you into a superhero.

Any guesses?

[grannylib]

1. looks like some kind of crab spider

[Orrex]

2. Thanks for the input

It just occurred to me to check Penn State's etymology page. Here's a listing for the Woodlouse Hunter that looks rather like the spider I found:
http://www.ento.psu.edu/extension/factsheets/spider/dysderidae.htm


Thanks again!