What's the rarest or most unusual computer-related item do you own?

[Alan Perry]

My most unusual computer-related item is an Axil 320 (SPARCstation 20 
clone laid out like a SS10 on the inside) running OPENSTEP 4.2. But it 
would be nicer if OPENSTEP made use of the second processor module in it.

Or the receipt for the very last magneto-optical cartridges for the NeXT 
that Canon had to sell.

If I had something rare, I would donate it to an appropriate museum.

alan