rhtexfish, that is sort of species dependent and the nature of the attack. With a black bear, you fight regardless of the nature of the attack (likely predatory or exploratory in nature). Brown bears are a little different. It's more likely to be a defensive issue, in which case you want to be neutralized as quickly as possible, just protect your junk. Keep in mind how they test neutrality, they "rake the genitalia" (not kidding, and I haven't said it on here in several years). If it is predatory in nature, ie you were asleep, you fight with everything available to you.
Mountain lion you fight, and you actually have a pretty high probability of success. I'm not sure where the misinformation that if a mountain lion attacks you it is a forgone conclusion you are dead comes from. Folks have effectively fought off mountain lions most of the time, compared to the alternative.
I know some of yall like to poo poo the pepper spray, but it has been proven to work extremely well. I used to spray them at close range, often with them fairly pissed off, and it worked like a charm.
[This message has been edited by ursusguy (edited 3/1/2012 8:54a).]