Assuming that everything is running on the same AC circuit, and located nearby, any old buffer circuit will do the trick. You want to make it so the high impedance source doesn't get loaded down by too many destinations...you're not fighting issues caused by long runs of cable, RF interference, or different AC circuits.
The ol' till.com JFET buffer takes about $2 of parts. There are a bunch of variants that use MOSFETS floating around, too.
The AMZ super buffer is an interesting take.
http://www.muzique.com/lab/superbuff.htm
It could also be adapted to a multiple-output active splitter by disconnecting the opamp outputs from each other, and adding more output coupling caps, which starts to look a lot like this:
http://smg.photobucket.com/user/gyraf/m ... r.gif.html
Finally, if you want galvanic isolation, Jensen have a fancy transformer coupled one:
www.jensen-transformers.com/wp-content/ ... /as014.pdf
Heck, just plugging into an average Boss pedal looks a bit like the Tillman preamp, with a JFET buffer on the input, and a BJT emitter follower driving the output. They're always active, even when the effect is bypassed.