For travel, my favorite is a Spyderco Pac Salt with a yellow handle.
The yellow handle identifies it as a friendly tool, yet the Pac Salt is still large enough to be versatile. It's also not cool enough that it will be confiscated/stolen, especially if it's already scratched up. Even if it is, you're out $60- about a tank of gas. Well worth it to have a Spyderco with you when you need it.
Add a Leatherman Squirt on your keychain for small utility tasks, and a Fold A Vee in your suitcase for edge touch ups, and your set.
Most important thing though is a LED flashlight that takes AA batteries. Being in blackouts over seas sucks without one; with one you'll feel like a boss.