We bought one of the traditional travel cots but found that it was too bulky for travelling as when it was combined with the pushchair the boot of the car was almost full. We have just purchased a samsonite travel cot (
http://www.kiddicare.com/webapp/wcs/stores/servlet/productdisplayA_42_10751_-1__1537_10001_) and it is really small and light. We have just used it for a trip to Scotland and managed to erect it in all of the hotels which was good as one of the hotels wanted to charge 10 a night for cot hire.
We are also going to take it abroad with us as it will allow Thomas to sleep in a familiar bed.