"Why, certainly, officer..."
Although it is temporarily out of stock at Entertainmentearth.com, you too can secure your very own official set of SHIELD credentials. They come in a handsome embossed leather wallet and include the metal badge and two ID cards: one for Nick Fury (the Sam Jackson version), and a blank one for you to complete!
Yes, you can be an Agent of Shield!
Unlike many Marvel prop replicas, this is a pretty reasonable $39.99, which isn't too extravagant. You want one, don't you?