The most famous example I can think of off the top of my head is the way the Edge from U2 uses dual delays.

1 delay for a single note repeat and the other delay for the dotted 8th.

there is also a LOT of cool stuff that can be done by using the "Fibonacci" number sequence, check out these videos:-

http://forum.eventide.com/cs/forums/p/6880/30374.aspx

The really cool thing about the "Fibonacci" numbers when used with delays is that they do not seem to be as reliant on correct tempo.

Have fun