+1Waxing = good.
I have been experimenting with Squirt (wax-based lube you squeeze on to the chain like conventional bike chain lubricants).
If it is mid-week and the chain starts making "wax me now" noises on my S40 commuter I put Squirt on it.
It's not quite as good as re-waxing the chain, but the chain stays almost as clean, it works well, and takes less time than switching chains.