Spray paint them with several coats of high gloss polyurethane.

Are you sure you want to make them shiny? It's true they're nicer when wet, but if they look wet when it's not raining it might look a little unnatural. You could always consider installing a little water feature to make it a wet creek bed and keep them wet all the time (or spray them with water before company comes!)

Hi again,
I talked to the landscape designer who drew our plan. She was very much against the idea of coating the rocks in our dry creek to make them look wet all the time. I think she is right...it would look too fake and artificial.
Thanks again for the responses.

2008 kitchen to remodel

Use a motion sensor device to turn the water on the rocks.

Mike...The original post is pretty old.