> Has anyone had any luck setting up empty hive bodies to
> attract swarms when they occur? Are there any better ways to do this?

These are more properly called "bait hives".  Sometimes they work, sometimes
they don't.  There are optimal placements for bait hives, rule of thumb
recommendations run about 10 feet off the ground, facing south/southeast.  A
beekeeper friend has routinely placed a bait hive out for as long as he's
been keeping bees.  He is now a senior man, he learned keeping bees as a boy
from his father.  The only time he caught a swarm on his bait hive was a
time the swarm settled on the platform supporting the bait hive.

On the other hand, I have had swarms settle in bait hives in my driveway 3
years in a row, until my local village goverment forbade me to keep bait
hives (or any beekeeping equipment) in my driveway.  Hopefully the next
swarm will settle in the mayor's living room.

Good attractants for bait hives are old comb.  Pheremone lures are sold by
some supply houses to attract swarm to bait hives, but said lures receive
mixed reviews.  Some herbs will attract swarms (bee balm and perhaps
borage).

The best advice for the placement of bait hives is to have them in place
well in advance of the swarm.  Scout bees seek new locations well in advance
of swarm issuance.  Scouts will even start defending potential new homes
(bait hives) days before the hive swarms.  You might notice activity at a
bait hive tipping you off that a swarm will arrive in the next few days.
Then again, you might not ever get a pay off.  It's luck of the draw.

Plenty in the archives on "bait hives"
Archives can be searched at:
http://listserv.albany.edu:8080/cgi-bin/wa?S1=bee-l

Aaron Morris - think a colony at home is worth two in a bait hive!