You can get a power cord at any electronics store that will fit into the hole, it wont be fancy and white but it will fit and it will work. Epect to pay around $5.99. It wont be grounded but thats not a big deal.Hey I was just wondering if anyone knew where I could buy those macbook power cord extensions? You know you can slide off the socket on the magsafe power adapter and put one of those in place.
I tried the apple store / eBay with no luck.
Edit: The left side of the following picture:
I'll also suspect that you can order it as a replacement part through apple. Expect to pay an arm and a leg.