Actually, you can join USPSA at the seminar, if you aren't already a member. The instructor will have membership forms--just write the check to USPSA, and he'll send it in with the class paperwork. You'll be listed as "pending" on the roster, but that gets corrected as soon as your membership is processed, and when the HQ staff processes your certification paperwork, you're good to go.
Troy
Excellent info, thank you!