This has to be one of the coolest custom products ever, custom metal cufflinks from Eleven Forty Design. They are individually modeled from a picture (or you can pick from your favorite person from their portfolio which includes Einstein and Flash Gordon). Each sleeve would have one side. Put them together and they create a little portrait bust. Imagine your toddler, your dog, or your favorite superhero immortalized on your cuffs.

This would be an interesting category of products for a custom engraver (or laser "tattoo" artist) to have. Send in a picture and they engrave it onto a flat silver cufflink. Probably would be a lot cheaper than this sculpted design, but just as personal.