So, what did everyone do with their challenge coin from Soild State? Mine went into a drawer along with my Scott Pilgrim coins. I suppose in the traditional sense you're supposed to carry it with you at all times. If I carried all my coins with me I'd need to wear another belt.
Not that the coin is not neat, it's just not very useful. The other things in the Solid State package all had various uses. CD = listen. Book = read. T-shirt = wear. USB card = way to spend 30 minutes trying to figure out how to open it without breaking it.