Even if Runner's knee and not ITBS, they are pretty much the same... Tight outer side(ITB) and possibly weak VMO (inner Quad). Neither will do much damage if you run, just lengthen recovery.
The brace/sleeve (I refer as brace because the fingers find those keys easier but really one in the same for this discussion) the Doc referred to is a good way to go. Though, there are several ways to skin the cat. The advantage of the brace is the neoprene-like material will warm the area, help promote blood flow. I have found that if you opt for one with velcro straps on both ends, it tends to stay up on the run where one without may roll and fall down. The open patella keeps you from smashing the knee cap into the joint.
I also like the ChoPat or strap type of sleeve. While I have never worn one more than a run or two, they will help keep the ITB in place and lower the inflammation.
The old school now new age way to attack this is through taping. Way back, all was had for an overuse injury was to tape the knee. For the ITB, it took 3 or 4 pieces of stretchy tape applied before the run or play and it helped the injured area feel better. Today KT Tape has created a new market niche thanks to a shoulder issue in the 2008 Olympic volleyball tourney. It is basically the same thing we did in the 70's and 80's but with pre-cut, better sticking tape.
This vid shows how to tape the outer knee.
http://youtu.be/f76B0j_bz5E