Cache Maine has a Photo Album TB I believe. It's been to a bunch of events but isn't always there.
When we were at GW5 we saw loads of different and very creative TBs. Many different cars with TB decals (huge) and other attachments with TB numbers. Cars of all sorts and styles. There were stock car tires, wheels with TBs, paintings with TBs - and lots of creative things. Even folks wearing huge necklaces that were TBs. TBs are only limited by the creative juices of the creator so to speak. Now if I can find my GW5 photos so I perhaps could post some photos of the TBs - I know I took a few.
Now an event to bring the most unusual, creative TB - that is an interesting concept. Keep us posted!