I bought a pack of these, they are exactly the same shape as the OEM protectors:
http://cgi.ebay.com/For-Sprint-HTC-D...3A1%7C294%3A50
Comes out to a little over a dollar per screen protector with free shipping.
I like that the product has a film on both sides of the protector, so you peel the one side off, use a credit card or something to put it on and get all the bubbles out, and when your happy with it you peel off the outer cover......put mine on in a steamy bathroom and it came out great