I use some finish line lube or just some teflon based grease to work some into the chain. I hardly lube my chain and commute daily. I get a tiny bit of rust if I ride for long periods in the rain, but after a few miles the rust wears off and the chain is OK. I guess I lube it once every few weeks / months.
How I miss those days when I would actually use muck off to make my casset and chain look brand new after every couple of rides.