I've been obsessed with anything in a jar for awhile now. I've seen this idea popping up throughout the net....what a great idea for a picnic/camp out. You don't have to pack all your ingredients in separate containers, but can jar it all up either in a large jar, or smaller jars.
The key is....put your dressing at the bottom of your jar, then put something like carrots, or celery (something 'sturdier' that won't wilt over night/in the cooler swimming in dressing. I put a layer of dressing/carrots/celery, cherry tomatoes, then the lettuce. You can leave a little room at the top if you want to shake it in the jar and eat it as is, or dump it on a plate and the pouring will do the work for ya. You can toss these right into the cooler...that's my kind of no stress, no mess meal.