I take alot of fast action pictures and just picked up a D70. I'm not shopping for a better lense, since the 70mm that came with the camera just won't zoom in enough. I goto alot of dirtbike, car, football, and basketball games, so I need a fairly fast lense.
What do you guys think about the Sigma 70-300 4-5.6 lense? I would like to keep the price under $300 or so. Would this be an OK choice, or would you recommend something else?