Arthur Chang has written a set of add-on rules for playing massed battles with the Wizards of the Coast rules for Star Wars miniatures.
This site has a nice selection of paper miniatures for both the new Star Wars movies, as well as the classic trilogy. They would be great for using with West End’s old Star Wars miniatures game.
Just in time for Revenge of the Sith, the Singapore Napnuts offers Senator Arjuns’ Star Wars Skirmish Rules.
Star Wars Silent Death is a set of modifications for the excellent Silent Death rules for the Star Wars universe.
Boonta Eve Classic is a set of free wargmes rules for pod racing in the Star Wars Universe. The rules are designed for use with those old Galoob Micromachines, which can still be had for a reasonable price on Ebay: