If you are staying at a hotel on the trip, ask at the front desk. Many have boxes of chargers left behind. While finding one for a think pad is a long shot, somebody may have left one. You can probably pick up a few Cell phone ones though.

Radioshack will have some in the $35 to $50 range, and as mentioned the other stores will have them too. You want to make sure there is a tip for your machine included or you will need to buy one of those too. Pricing will be all over the place, so hope one of them is on sale or something.

If there's a Best Buy Kiosk or one of the electronic / cell phone stores in the airport, chances are there will be some there.