Games for travelling

Let's get a thread going for a list of portable games that travelers may want to have with them.

Munchkin is a good one. It's 2-6 player card based game where you kill monsters, collect items and treasure, and screw over your opponents.
http://en.wikipedia.org/wiki/Munchkin_(card_game)

My son just loves munchkin, he's got lots of versions of it. It's easy and silly and portable.

I would also recommend Palabra. It's like a scrabble-y card game. You have cards with letters and colors and stars. You make words from the letters in your hand and get extra points from the colors and stars. You can even build on others or do straights. Lots of fun for the wordy among us.

Uno's good too. It's something you can play without needing to have much of a common language.