This is a fun event that will give you an opportunity to experiment with that SPLIT button. Listen on the MARS freq, the operator will announce the specific Amateur freq the station is monitoring. And the next time the DX says 'Up,' you'll know how to do it!

http://www.arrl.org/news/annual-arme...led-for-may-12

And if you're concerned about legality, it is specifically authorized in Part 97.111(a)5.