I visited this great place in Toronto to refill my laser printer cartrdige.
I admit, i used to throw away my old cartridges, but these guys refilled it on the spot and it works good as new.
The name of the shop is "Cartridge World", located on Kennedy Road + 401 in Scarborough.
Phone number is 416-412-FILL
They also refill inkjet cartridges, general pricing is about half the price of a new cartridge. I guess they save money and the environment ;)
Worth a try in my opinion.