The best way to do this is to get every person in the band on in-ear monitors. Then have one click source, and route that click source into each person's individual mix. One of the best in-ear systems for churches out there now is Aviom. But it can be pretty expensive.
A cheap way of doing this is to set up a Headphone distrubtion amplifier, and run headphones to each band member. Check out the Presonus HP60
 

What we have done in the past before our church had in-ears for the whole band was the drummer would count the song off with a soft ride or hats and keep tempo that way. It never got in the way of the dynamics of the song if the drummer did it right.

andrewalker, we do that now. Segues between songs is not smooth.

mattmccoy, I don't think headphones are practical on stage but maybe an earpiece from the HP60.

Just got an email from the worship pastor. This might be the ticket. It's wireless and inexpensive at $130 a piece.

http://www.strobostomp.com/index.cfm?category=163