Good points here. To me role models are at the top echelon of their craft, their success inspire and motivates. Mentors, in contrast, are at the "next level" of where I want to be. They provide the nuts-an-bolts how-to for achieving that next level. Both are very useful.
For example, if I was an novice lead singer in a band just starting out I'd use international rock stars like Bono and Dave Matthews to inspire me to practice, but I wouldn't study their concert DVDs or pour over their autobiographies. Instead I'd seek out advice from singers in bands that had made an album and were playing in bars and clubs around town, the next level for me. Steve has great examples
on how to do this.
And yes, there is a danger of building an idealized image of a role model when you don't really know them. One of my male role models, a man I strove to emulate, turned out to be a woman. Loooonng story.