You know those people who religiously stretch after every workout, and enjoy it? I'm not one of them. I have historically avoided stretching at all costs, and only due to sheer guilt resorted to using the otherwise untouched stretching chair at my gym. This all changed when my lovely trainer (Callie at Equinox San Mateo) insisted that I give the foam roller a shot as an alternative to traditional stretching.
She had me at "alternative to traditional stretching"...what I didn't expect, was the fact that this foam roller actually hurt...and it hurt BAD. It turns out that this tool actually is an alternative to a sports massage. It stretches muscles and tendons, and also breaks down scar tissue. It breaks up painful trigger points, soothes tight fascia, increases blood flow and circulation to the soft tissues, and DIMINISHES CELLULITE! Yes, you read that right. Not sure how that works, but I'm thinking that the combination of increased blood flow and massage makes those dimples go bye-bye.
How do you get started with the roller? It's fairly easy - you simply move the foam roller and body to stretch your back, your glutes, hamstrings, IT bands, shins, and calves. Also, you can opt for the traditional rollers (longer and are made of, you guessed it, foam) or the shorter Trigger Point alternatives that have some beneficial features associated with the varying densities across the roller.
This piece on Runner's World gives a great overview on how to use the roller and includes great videos: http://www.runnersworld.com/running-tips/roll?page=single Enjoy!