31January 2011
10 added screen effects (instantaneous patterns and average intensity patterns)  of the interference patterns for both coherent and incoherent sources from http://www.cabrillo.edu/~jmccullough/Applets/OSP/Oscillations_and_Waves/waves_interference.jar by  Juan M. Aguirregabiria. now it is very easy to visualize the meaning of coherent sources. :)

sick today so at home.

i also found good resources
http://phet.colorado.edu/en/simulation/wave-interference [img]http://phet.colorado.edu/sims/wave-interference/wave-interference-screenshot.png[/img]
Like: a lot of possibilities
very complex and realistic

http://www.cabrillo.edu/~jmccullough/Physics/Interference_Wave_Nature.html
collection of good applets