I just replaced my Logitech weather cam, with a used, "broken" Olympus 4MP camera I found on eBay. It is broken in that the LCD on the back does not work (but who cares when it is a weather cam).
I cannot believe the results! I do lose the ability to have a live, streaming camera, but I gain resolution and unbelievable low-light capabilities. At night, when it is cloudy (and the light pollution from the city is refelected back) it looks like daytime on the camera.
I am also experimenting the compression on the time-lapse videos. Now that so many people have broadband internet access, I'm making the videos a bit larger for better quality.
View the camera here: http://itsyourweather.com