A few years ago I had the same problem really bad.
I actually wrote an article and heard from tons of guys in the same boat.
"Open letter to the women of the world: Re: Helping me have orgasms."
http://prehensile.com/does/orgasms.htm
bottom line, I was obsessed with making her climax. But condoms are still a problem. I have to be on the brink via mouth/hands before I put the condom on. I also try to have the package open and ready to decrease the energy-crushing lag time of grabbing the condom.
Good luck.