You know, i have listened to this issue and the debates on it over the years, and I have been leaning towards this;
I believe (and I am not by any means totally all in on this) what we are calling the baptism of the Holy Spirit, which appears to come either at conversion or some later date, is the administration of gifts by the Holy Spirit.
When a person gets "saved" they receive of course the Holy Spirit of God, the Spirit of Christ, Father God. What we see as a baptism of the Holy Spirit could be viewed as the administration of gifts, which the Spirit may give at conversion and at a later date.
We are told to ask for gifts, correct? This tells us we can obtain gifts AFTER conversion. Let's say you are given the gift of healings, what would this look like? Wouldn't others see how the Holy Spirit is with you? Couldn't you say "I have been baptised by the Holy Spirit, given the gift of healings" ? Isn't this even what Pentacostles would say?
But then time goes by, and this same person has been coveting earnestly the gift of tongues, and bamm! The Holy Spirit comes upon them and the gift is manifest! Would this person say they have been baptised by the Holy Spirit a second time? And coudn't there be a third time and a forth?
I am beginning to see this baptism of the Holy Spirit, not as a one time event that should be sought after and somehow you feel like you have "made it" with God when you receive a gift.
Isn't preaching and teaching a result of the baptism of the Holy Ghost? How about the gift of servant? The humble christian who gets no recognition, but faithfully serves behind the scenes? No great "power" gift, or is it?
It appears there are many diverse gifts given from the very point of conversion. And also gifts given after conversion. Some of these gifts are very "powerful" to the public eye, some not so much.
Does God call all Christians to have the so called "power" gifts? I think not, I know not. But it does appear to me that every Christian has been baptised with the Holy Spirit at conversion and given gifts for the edifying of the kingdom. AND, the Holy Spirit gives additional baptisms, calling some Christians to service in differing areas at differing times. Giving some gifts, such a miracles, to convince say a pagan crowd in some foreign land that the preacher is accompanied by God! Or even Christian man is called and baptised by the Holy Spirit to become a pastor later in life. We cannot view all of this from our little world here in north america, God is doing things like was done in the book of Acts in other places in the world going into all the ends of the earth. Talk to some missionaries sometime.
So I think we might be wrong to view the baptism of the Holy Spirit as only a one time event in a Christian's life. As an event that only happens either at conversion or afterwards and can only happen once. I believe in the baptism of the Holy Spirit, but I think we are getting it all twisted around into something it is not.
Alright, thoughts have been emptied out, Godspeed!