We bought my boys Ready Beds from Walmart for this very reason. I knew that if we had a hotel room with 2 queen beds, that they would not be able to sleep together (one is restless and wakes often) and they're big mama's boys so they would both want to sleep with me, meaning that I wouldn't get any sleep.
The Ready Beds have been great. They have them in several different themes. My boys have Spiderman ones and they think it's a special thing to get to sleep on their Spiderman beds. We bought a small portable electric air pump and take the beds with us whenever we're going to be staying away from home. When we stay at a hotel, we get a room with a king size bed and put the Spiderman beds on the floor on separate sides of the king bed so they can't see or touch each other... they fall asleep much faster this way :).
Here's a link to the Ready Beds:
http://www.walmart.com/search/search-ng.do?search_constra...
I had to order them from the website, but chose to pick them up at the store so I didn't have to pay shipping.
HTH!