I lost the cable that connects my digital camera to my computer so I can dowload the pictures from my camera onto my computer so... now what?

Card reader would be my guess, or eBay and buy a new one.

If you don't have a memory card... then you would have to buy a new cord. Any camera store would have them, and depending on the type of camera other stores may carry them too. But to save money, you could do as Curlyben said and check on eBay.