UPDATE:i want to make a little update if i could;
i had a vibration problem for a while. Since i'm a cheapskate and the vibration wasn't THAT bad, (Actually, i was very noticeable, but again i'm a cheapskate) i put it off until last week, where it just got TOO bad. (also see the other thread, "best inexpensive tires for everyday driving.")
In the process of trying to determine the problem i noticed that i forgot that i had used the Counteract balancing beads in three of the wheels. The forth was Hunter road force balanced which i think is wonderful. But i wanted to try the counteracts.
It was determined that one of the tires had bad bulges in it and this was the cause of all the vibration all along. i recently replaced this tire and put the balancing beads back in, and the truck now rides pretty smoothly.
So, based on my experiences, these balancing beads do seem to work:
http://www.counteractbalancing.com/