i've had IT band issues for about 6 years now so the following is what i've found that works. it started after 16 mile hike one day. it's very treatable and only comes back when i'm inactive due work/life and get complacent on dealing with it for periods of time.
-sorry in light of eric leaper's BS book spam fest here but get either a used copy of The Pain Free Triathlete by Julie Donnelly or her more recent book that is more broad based sans athlete Treat yourself to Pain free Living by her as well. It discusses all the treatments through deep tissue massage, stretches, what areas to focus on, ect. Treat Yourself to Pain-Free Living (Print) - Books
Working out the knots that are pulling the IT band tight is one of the big keys to getting rid of IT issues. Think of your IT band as a rubber band. Knots along the outside of your thigh and in your gluts are pulling it tight along your knee causing the band to spasm and inflame. the key is to loosen that up.
the deep tissue massage will hurt like hell when you find those knots. keep at it with a foam roller. eventually you'll want something even harder like a PVC tube or for in the field work, a nalgene bottle. it sucks. it hurts. there is no way getting around it. there are vids on youtube these days, as well... "IT band foam roller",ect. allot more info these days than just 6 years ago, for sure.
the other long term angle is to start cross training. adding in biking has been my biggest help and maintaining it/balancing out muscle groups,ect.
since part of the issue is pain from inflammation, don't be afraid to down some anti-inflammatory stuff like Aleve while building up your core strength and working through it.
the patt strap helped me too while rebuilding strength and long backpacking trips. it's not a cure, just an aid.
fabrifoam? Products - PattStrap
the biggest thing to understand is with ITBS is that the location of the pain(knee) is NOT the source of the problem. the source is higher up in your thigh,gluts and psoas muscles. This is such a key concept to get in your brain about treating it.
also, don't dismiss/confuse deep tissue massage or trigger points,ect with some mystical, get-in-touch-with-your-shakra mumbo jumbo or whatever. this is just straight,effective sports medicine. and it will hurt. allot. but it's all better than the baseball bat to knee feeling when your IT band goes into spasm, for sure.
good luck with it and feel free to ask away here or via PM if you have further questions.