You can also buy clear switchplates, like here:
http://www.myknobs.com/creatwalplat191.html

Where you don't have to cover the switchplate itself, the wallpaper piece just slips in between the clear cover and backplate.

Here too, scroll down to wallpaper switchplate:
http://www.decorativehardwarestore.com/switchplates.html

nice lightswitch camoflauge

Painted over switchplates are nasty and implies lazyness. I have never seen a painted over switchplate that looked any good closer than 50 feet.

Wallpapered switchplates, as pictured, do work well.

I think the paint over method only works if it isn't literally simply painted over with a standard roller/brush. It needs to be removed and painted separately and a small brush used to get all the tiny areas to make it really look seamless.

oh, and don't forget to paint the screws too!

Enamorada, very true. Obviously I've been in some cruddy places where they've been rolled over hastily. Plates removed and painted with care could be nice.

Wow, I love those clear covers. I've never seen those before.

Such a great alternative to the standard white, which always seems to end up (sloppily) painted 642 different layers of colour. Can you tell I've rented?

I'm painting this weekend and was thinking about this. I'll probably back-paint a clear cover and leave the outlet/switch... i think it would be really hard to make this look right.

Funny i accidentally smashed my coverplate a week ago and was going to replace it anyways.

Painted outlets and switches reek of landlord cheap, and are just plain tacky... I could see a back painted clear outlet/switch cover, but please don't encourage outright painting them.

"Painted outlets and switches reek of landlord cheap, and are just plain tacky" <- Would you rather have your boring white ones?

ew i really dont like the look of that. it is so much more noticeable knowing its there in some odd way

i should clarify- the painted ones are fine in my opinion, but the wallpapered one is wierd!