Can we prove other people exist?

It is tempting sometimes to think that other people don't exist. If it's been a bad day in the office, or you just did something particularly embarrassing we can seek solace in the fact that perhaps it didn't really happen. Or maybe at least comfort ourselves that there is a parallel universe where everything goes right for you and you're having a pretty fun time right there right now (though on the flip side this incarnation of you will never be able to access that you. Too bad.)

For practical purposes, it is quite convenient to assume that other people do exist. Otherwise you are liable to totally ignore others and have no consideration for them which is a little tricky unless you live in the middle of nowhere and grow your own food.

However, philosophically speaking, can we ever prove that other people exist? Can we even do what Descartes did and show at least beyond reasonable doubt that we exist - is "I think therefore I am" a valid statement? Or does the fact that there is something thinking even mean that something exists? Discuss.

Re : Can we prove other people exist?

Any thoughts anyone?