A: Only what you bring with you.
StarWarsPhreak is correct as is Astrotoy7. Luke was poised to potentially attack Joruus C'Boath, when the crazed clone jedi master killed all of the ysalamiri. Then Luke sensed a disturbance in the force, his own clone. According to the Thrawn Trilogy, clones go insane due to the shared mental bandwidth. Of course this is pretty much debunked in AOTC when we find out not only is Jango the host for the clones, but as well as for Boba Fett, and he's not insane.
Anyway, Luke duals Luuke. Luke holds Luke's lightsaber, whereas Luuke holds Anakin's lightsaber. Luke gets immobilized, and Mara jumps in. If memory serves, she holds Luke's lightsaber, while she duels Luuke holding Anakin's lightsaber.
If you want to be technical Leia was holding Leia's lightsaber, but she wasn't dueling.
O.k. here's a harder one
Q: This one has two parts.
Q1: Where and when was the first time Han Solo met Senator Garm Bel Iblis?
Q2: What was Han REALLY doing there?