I like to think of it as karma. I had two offers, and I was also on the wait-list. So I turned down one of my original two offers in the hopes that someone would do the same for me at the other schools.
I was in the same position as the guy who wants to hold onto all of his offers, just out of being risk averse. But I can tell you, that is all irrational. Even though I didn't want to turn down one of my offers, I knew one offer dominated the other.
If you can't decide on an offer right now, how is it going to be different waiting several days from now? All you have to do is make a campus visit, ask some questions, and then compare them.
Turns out karma worked out for me. I turned down a top 100 program, and the week after that I got an interview and offer at a top 25 program (according to UT Dallas). To make it more interesting, there were 10 schools I applied to between 25-100 that rejected me.