Better chain lube is good, too. I ride in the rain most of the year. I use Finish Line Ceramic, this stuff:
http://www.finishlineusa.com/product...c_wet_lube.htm
It's amazing. I never have a rusty chain. It is important to wipe the gunk off the chain from time to time. I'll add a bit of lube from time to time, and thoroughly clean and lube every couple weeks. At home, I use a Park chain wear checker and replace the chain when it shows a good bit of wear. Of course I don't carry that tool when I tour, so I'd probably replace the chain every couple thousand miles.