I see black bears occasionally on my morning commute. Brown bears much more rarely, usually when the salmon are running in Ship or Campbell Creeks. While it certainly gets my heartrate and cadence up a notch, but for the most part they look at me, say "too fatty", and get back to whatever they were doing. I did have stare-down with a juvenile brown (slightly taller than am)a couple years back (he was put down a week or so later) where I didn't want to trigger the chase instinct. I came grunting and wheezing up the hill, turned a corner, and there he stood- slightly perplexed by the sight. He moved off after a few tense moments. This was a couple blocks from downtown Anchorage. After a local cyclist was mauled during a 24 hour mountain bike race last year, I'm a little less bold in my dealings with bears.

That said, I'm generally more scared of moose. They're much more unpredictable and common.