Which cards take up more then one slot and is it better if they do?
Well, the 8800GTS 512MB and above usually takes up 2 slots. Some aftermarket coolers for the lower end cards, like the 9600GT takes up two slot. Generally two slots indicate better cooling, so to us OCers it's a good thing.
Most of the time, buying an after market cooler for a GT card brings the final cost close to the cost of a GTS, but without the added performance (unless you overclock, but then again, you could also overclock the GTS). Don't buy a GTS on tigerdirect tho, you will pay more than you should, go to www.shopbot.ca, you can probably find a GTS for ~230$.