As if there aren't enough email scams to be wary of, Boing Boing has details on the latest PayPal scam that uses an IE URL spoof to seem 100% legit. Take a read if you're a PayPal user (includes screenshot).
My only advice for avoiding scams like this is to always double-check the site in question. In this case, visit PayPal.com and see if everything checks out. Be careful out there.