Here's a tip from Marylaine Block's Neat New Stuff: "everystockphoto.com is a search engine for creative commons photos, located in Vancouver, BC. We aim to be a community for designers, developers, photographers and other media publishers who want better, easier access to license-specific media on the web."
Once you've found a good photo, have some fun with Polaroidinizer - you just enter the url of the image, add a text, and Polaroid-o-nizer produces a signed snapshot like the one on the right. Polaroidonizer can also be used for more legitimate purposes, e.g. promotion of embassy/irc events, email invitations, or personalized photos for thank-you notes the Ambassador wishes to send to people he/she has met.