I've seen a great deal of street fights and have been in a few (all of which happened before I took up boxing). In most cases I see sluggers just come straight in and throw alternating haymakers. My question is if someone was coming straight in on you what would you do? Would you circle left or right and Jab? Would you stand your ground and duck under the cross and land to the body? My friend is a big BJJ guy and he says when you see the guy wind up to duck down and then you're in perfect position to take the guy to the ground? Would a boxer have the upper hand in a street fight or do boxing techniques not apply well to the street?

I think you need to differentiate between a fight and self-defense.

A fight is based on mutual combat between two people and can usually be avoided quite easily as long as you don't have a fragile ego. Agreeing to fight "one on one" is just plain dumb. You have no way of knowing how skilled the other guy is, plus, 9 times out of 10 you will wind up with broken hands and in jail.

Self-defense is something that can be honed with proper awareness of your surroundings and good verbal skills to talk your way out of trouble. Most attackers/muggers etc. will use some sort of dialogue before attacking in order to find out if you're a good victim or not. This is your best time to use your verbal skills and body language to show him that you are not a good target for him, and that you don't want trouble etc. If this fails, and the attacker is still agressive, then you need hit first and hard with one or maybe two techniques that are comfortable and powerful to you, then run. Aim for his jaw and crack him when he isn't expecting it, then run like hell. If you're on target, and get the jaw, he'll more often than not, hit the deck very hard and be out like a light. Forget the movies where you finish him off then call the police. ALWAYS avoid police involvement and get the hell out of there. Self-defense is about survival and getting home safe, not winning a "fight".

Menapace is on the money.

You focus should be on defending yourself, think about your exits and try to keep your mobility. I like the idea of taking them off of their feet, but not following them to the ground, just running away.