I would like to demonstrate what you can do with Gimp in creative photo manipulation.
Gimp is a very powerful tool

Here’s the photo we’ll start with:

The photo itself is very nice – but the only thing that annoys me are the people all over the beach.
(I guess they were annoying at the time when picture was shot as well ;)
Ok – let’s clean it up a little.

We’ll work with high zoom (400%) using Clone Brush tool – with options set as on the screenshot.

Technique of using a Clone Brush is very easy to show, and quite hard to master.
You won’t be able to clone any backgroud – only the repeated textures will do (like water or rock in this example). You need to clone large areas so it look natural, but you should make sure to clone out any specific patterns that are easy to recognize.

Remember about the details – like taking out reflections in the water.
(I actually miss reflections on the wet sand at right side)

As I said – remember not to leave cloned patters that are easy to spot (remember those cloned iran rockets? ;).

We continue to clone background areas to other places – hiding what we would like to hide (tourists in this case).

Final touch is to boost Saturation and Contrast a little – and we have it ready.

Before (click to enlarge)

After (click to enlarge)