There are loads of TBs (travel bugs). There are the classic TB Dog Tag which you can attach to a large variety of objects to send out into the wild blue yonder (like the CITO travel bag
I posted about earlier). I've seen oodles and some creative ones as well. Belt buckles, models, toys, trinkets... Jaxie crocheted some peas and carrots for our Forrest Gump cache and the guy who found them attached a TB and sent them off again as a trackable item.
I've got one atached to my GPS which I "dip" into most every cache I find and I can track myself as I go from cache to cache.
They make T-Shirt TB's, Hat TB's, and TB's to go on your car. Now essentially, these are no different from the TB dog tags people attach to their items, they're just printed or sewn onto an item you wear or drive or carry with you.
Enter the Muggle Family Vehicle Travel Bug. I've blocked out the tracking number, if you'd like to "discover" it, spot us in a crowd. Don't forget to tell us where you saw us.