First, thanks for sharing your story Webdude.
Second, hottwheelz, I suggest you find out a bit more about Christianity from someone other than a door-to-door religion salesman. Your summary of Christianity as a whole is oversimplified and biased.
Now on to the subject. I've never heard a voice that said "Dude, this is God, and you need to do this. C'mon. Just do it." I don't believe God works that way. I don't believe that the same God who gave us free will would stick his voice in our head and say "Listen, this is God, so do what I say." Any person who really believes in God (or any person who believes in any God whatsoever) wouldn't even think about disobeying a voice that they were convinced was their God. Thus, I don't think God actually speaks to us in a booming, on-high voice. I believe that he speaks to us through experiences, through that little, not-so-booming voice in our heads, through other people, and such as that. I'm sure I've had experiences like that before, but the point of using things other than a booming, on-high voice is that you never know it's God
Now, I've definitely "felt God's presense," as some would say. My church has some awesome worship services sometimes, and I really have no explanation for the feelings I get when we have a really good service besides God's presense. It's not a Pentecostal rolling on the floor, swinging from chandeliers, speaking in tongues kind of feeling, it's more of a glowing peace. I dunno.
As for denying science, it's either a fear thing or an ingrained doctrine thing. For most of my formative years (especially since I was homeschooled for much of them) I was taught that evolution was impossible, that the earth was 6000+ years old, and that nearly all science was wrong. As I entered public school in my sophomore year I began to question these beliefs, and wedged myself somewhere in between the Catholic church's stated beliefs (that God started evolution and then let it run its course) and old-earth creationism (also called day/age theory, which suggests that the "days" in the Genesis creation account were much longer than 24 hours). Since then, I've decided that creation theories have very, very little to do with theology, and definitely aren't going to send you to hell, so I've stopped debating the points in my mind, and with other people.
(PS, guitarnerd posts the best threads.)