Strings sound in "Nude" on In Rainbows

[Wain]

If you're talking about what I think you're talking about it's some kind of synth effect, there are several similar sounds on a variety of software samplers and keyboards.  I'll dig around and see if I can find specific examples.  There is (or was depending on how it was built) a LOT of effect processing going on.

Definitely not strings though.

[Wain]

now that I think of it,

I have a friend who's into shoegazer who's managed to make very similar sounds from his guitar using an e-bow as well as whatever effects pedals he may have had running.