The article I linked to has this to say about using the foam roller for "stretching the IT Band." He does say it can be useful in massaging trigger points in the hip muscles, however.
The iliotibial band syndrome is a massive structure, the largest tendon in the body, made of a bio-rope stuff that is slightly elastic but with a greater tensile strength than steel cable. Collagen is an extremely tough protein. It cannot be elongated beyond its natural elasticity by any known method short of surgery, and certainly not by rubbing it or (even sillier) rolling over it. Here’s an absurd exercise to demonstrate how silly it is:
Measure a leather belt.
Stretch the belt on the edge of a table.
Grease up your elbow with some lubricant.
Slide your elbow along the length of the leather belt. This patient feels no pain: be as brutal as you like!
Re-measure the belt. How’d you do? Make much progress?
Now consider that leather is actually much less strong than tendon. Leather is cow skin — remarkably tough, but with a lower tensile strength than tendon, and much “easier” to tear. Tendons are so tough that they basically don’t tear at all, ever.74 Yet even if you halved the thickness of that belt, hung it from a strong hook in the ceiling, and pulled on it with all of your body weight, it would probably still hold you.
So … good luck trying to “elongate” the IT band with massage.