If you live in the US you should be familiar with the electronics store Fry's. I looked on their website and they seem to have Pokemon Platinum for sale. Check it out:
http://shop3.frys.com/product/5812043?site=sa:Homepage:Spot2
I'm gonna try to see if I can go to the actual store to see if they really have it in stock.
http://shop3.frys.com/product/5812043?site=sa:Homepage:Spot2
I'm gonna try to see if I can go to the actual store to see if they really have it in stock.