Here are a couple of links with good ideas for healthy lunches on the go:
http://thecheapskatecook.com/2010/08/17/healthy-easy-lunch-box-meals/
http://www.passionatehomemaking.com/2010/05/healthy-packed-lunches-for-work-or-school.html
http://www.kitchenstewardship.com/2009/08/18/packing-a-lunch-healthy-food-to-go/
And, a great list of snacks!
http://www.massagetherapyschools.net/blog/2010/100-healthy-after-school-snacks-for-your-hungry-kids/