You might also try some modulation and phase stuff on top of your delays.
My favorite delay is the Interruptor Tape Delay (pc only):
![Image](http://www.interruptor.ch/vst/tapedelay.jpg)
http://www.interruptor.ch/vst_overview.shtml
Comes free with white noise too, a bad ass plug. Put an auto pan and automate the send and feedback on this thing and its money.
Good tips on that site too.