You can make your own ID badges, press passes, and nice looking name badges by visiting BigHugeLabs. They offer an easy-to-use web interface that allows you to add your pictures and customize the text to produce a variety of badges that you can print or share electronically.
I'm not saying that one of these will get you on the sidelines of a pro football game, but ID does come in handy when working in the field. It lets people know who you are and what your purpose is. Plus, these badges just look cool.
The badge shown here is a sample of the Flickr Photographr template.