Quote - ...The only thing I can think of to speed-up your render time is to not use skylight, but simulate it with several distant lights. Depending on how you place your distant lights, you could get anything from a dull to a very good render, so you will have to experiment...

Yeah, that's pretty much what I've been doing, for the most part. I don't do much still work; most of my work has been webcomics and animation, so I try to get the best quality in as little time as possible. Using globals with shadow buffers and the right settings gets results that wouldn't be mistaken for Sky Lighting, but at least provides realistic ambient effects with some "pseudo" occlusion. Not a bad option.