We looked into buying a portable crib for Spud, when planning our trip, but he was already too big for any we could find. And we knew that the kinds of places we were staying, wouldn't have such sleeping quarters for our wee one. So, we brought a pup tent igloo-thing that we bought at IKEA for something like $15. I think they have castles now. Also cool.
Anyway, it worked better than we even thought. It packed down small and light. We were always able to find enough extra pillows and bedding to make a suitable little nest in it. We used mozzy net on the doorway when we were in mosquito country. Even though he often ended up in our bed anyway, there would always be those awkward hours where he's asleep but we're not ready to. By keeping him at floor level, we avoided any falling-out-of-bed scenarios.