Any time you go out to eat you're going to have to make some sort of compromise. Even if a restaurant says they're organic and the menu looks pretty clean, you still have little control over the ingredients and preparation that make up the entire meal. The meat may be grass-fed but it may have been cooked with an oxidative oil, or they may have added sugar to the meal along the way. The meal may come with grains or a starch that may look tasty as hell, but will most likely wreck your GI system. Do you order that meal anyway and try to eat around the offenders, or do you go in a different direction and get a salad and add protein to it?
When you're on vacation try to eat as clean as possible but don't shy away from small indulgences. I don't have much of a sweet tooth, but when I'm on vacay, the mentality is that I'm taking a break. As long as you don't go overboard and completely hijack your blood sugar, you don't have to feel bad about having a few bites (or the whole thing) of some non-paleo treats. Taking these mini breaks from time-to-time keeps you sane.
When traveling for work, I usually get a room that has at least a mini fridge if not a kitchenette. I find a Trader Joe's, Whole Foods or other comparable store in the area and stock the fridge with the best choices possible. Trader Joe's has pre-packaged hard boiled eggs in the same section as the regular eggs, which are great to keep on hand for breakfast or snacks in the room.
Paleo Foods for Travel
Jerky: Hard boiled eggs are fine once you've reached your destination but are just too stinky to travel with. Opening a warm tupperware container of hard boiled eggs on a plane is probably a federal offense. Jerky is a much better option for travel. Jerky is probably the perfect traveling protein. If you can make your own, that would be ideal; But not always practical. Most store bought jerky has added sugar, soy, and additives that are less than optimal. Something like Steve's Original Paleo Kit is good when you're in a fix, and they even offer grass-fed kits now. The only thing I don't like about them is they're really messy. I like messy food, but the Paleo Kits have a lot moisture in the package which makes for a wet mess in your hands.
Larabars: There's quite a bit of sugar (albeit natural sugar) in these little bars. As good as Apple Pie and Banana Bread are (and apparently Blueberry Muffin as well, although I haven't tried it), don't crack out on them. Still, they're a good whole food snack on the road.
Water bottle: Hydration is critical, especially when traveling. Airplanes have low humidity, and dry, recycled air, so it's easy to get dehydrated on longer flights. You obviously can't go through security with a full water bottle, but you can go through with an empty one and then fill it up at a water fountain once you've passed through security. You may need to take your water bottle out of your bag at the x-ray machine. Side note: For any of you mobility fiends, you may have your bag searched if you're traveling with a lacrosse ball and an empty Nalgene bottle. This happened to me on my most recent trip out of the Philadelphia airport. The screener saw a solid mass (the lax ball) on her screen and didn't know what it was. Avoid the hassle. Take an extra five seconds and take the lax ball and water bottle out of your bag before sending it through the x-ray machine.