I use one every time I go backpacking...in fact I just loaded it a couple hours ago. Even if there are no bears around, it keeps all the other critters out of your food as well.
Personally, I would take a bear can over hanging my food any day. Regardless of the method (hanging, bear can, bear bag), you want the food away from camp, so none of them have an advantage there. Accessability is greatly reduced if you hang the food, not to mention the PIA factor of actually hanging it...the bear can you simply pull from your pack and leave on the ground. The downside of the cans is that:
A: They aren't cheap (I paid ~$50, 8 years ago).
B: They are bulky (travelling solo, I can fit 4 - 5 days worth of food in the smallest one I could find).