This will not help you with sky exposure but have you considered a tripod or even an external flash ?
A tripod is a must for any low light situation. It's also useful for many situation when you have a slow shutter speed. I purchased my first one at futurshop for 40$ and manage to get some very nice pictures. I'm now using a Manfrotto 190XPROB and I never go out without it.
An external flash like is also very fun for low light situation. You can "mimic" normal light with bounces and they have far more options then the built-in one. I use my SB600 mostly inside but sometime I pull it out for fill-in.
Just some ideas
