I love MOO! I guess that makes it a noun and not a verb, and I have no idea why the company is called that. But Moo, Inc., is a printing company that I found on Flickr, and one of their specialties is the approximate 1" x 3" Moo cards shown above.
Moo cards have almost a cult following and are immensely popular as an alternate to business cards as you can have your pertinent info printed on the back. The best part is the front, which are slices you select from your Flickr photostream. Or, you can choose stock art, but it's so much fun to see your photos brought to life in tiny pieces.
I keep my Moos on ball and chain. I simply punch a tiny hole with my Crop-O-Dile and string them on. I have three chains: my art Moos, my Blythe Moos and Moos from friends. Moos are popular to trade at both art retreats and Blythe meets, and a lot of people enclose a Moo with Ebay and Etsy purchases.
If you'd like to swap Moos with me, just leave me a comment or send me a message. Mooooooo.