Threads crop up with some regularity discussing how to switch relays or motors, but without tying up too many pins. I've just been playing around with the Onsemi NCV7708B (see product page) and the more I use it, the more applications I can think of. It provides 6 high side and 6 low side switches controlled from an SPI bus. It's got all the automotive features you would expect like a 5.1V to 28V operating supply and it can handle 0.5 to 1.5A depending on conditions.