If you can manage to check in with SparkPeople while away, it helps. Also, depending on your situation, you may be able to plan some meals and snacks and take part of them with you to avoid temptation. Things like carrying some nuts or fruit in your purse can make a huge difference in how much resistance you might have to eating too much of the wrong things.
I have food allergies, so I have to be prepared for times that no food is available that I can or want to eat. That makes my situation a bit different than most folks.