I'd suggest other items to spend it on such as an item which displays a PPS version, just as one had suggested.
I apologize if this has already been suggested as I didn't read through the other posts, but I think a lottery of some sort would be fairly interesting. As well as donating C$ to the pound perhaps. If you want to be a little on the different side, you could use C$ to purchase more aesthetic features such as custom templates for your profile to appear on forums, much like Flight Rising.