Instructions on making flags looking real

[yarnos]

I currently have drawn the outine of a map of the island on Photoshop cs3 and now i want to fill the island with 2 country flags blend together within the island outline. Does any body have any tutorials or instructions how to perform this routine ??

 

[Nomission]

First blend the flags, forgeting about the island.
When happy, use the outline of the island to create a mask over the blended flags.
With the images posted will be easier to explain...

 

[sbdb]

Add both flahs on top of the map as clipping masks


Creating and Using Photoshop's Clipping Masks