I'm not sure what would be the best way to do this, but I need to be able to show the number og guests that are viewing the current page a visitor is viewing. No who but how many.

What would be the easiest approach to do something like this? is is possible to do this without a database, but maybe with a javascript or PHP?

The output would be "There are XX people viewing this page".

**Edit:**
Could this be done by showing the number of Unique Visitors the last 15 minutes? I wouldn't be 100% accurate but would work for my purpose