Check out this link: http://www.christiananswers.net/q-acb/acb-t004.html
Baptism of the Holy Spirit is basically another term for salvation. It happens the moment we are saved. It is the act of the Spirit that moves us from the body of Adam to the body of Christ. It's a once and done deal, since salvation is a once and done deal.
Not that I'm denying the experiences you guys are claiming. I'm just saying that those experiences are not necessarily the baptism of the Holy Spirit. You may have been moved by the Spirit in a special way, or felt His presence in a unique way, but to say it was the baptism of the Spirit is not quite correct.