It's also a specific instance of a more general technique of incremental computation, which is, if you look at it from the right perspective, a more specific instance of integration: rather than computing a function directly, you're computing the differences and then integrating. So you could almost say that the method dates back to the 18th century: http://en.wikipedia.org/wiki/Euler%27s_method.

It's definitely one of those tricks that comes in handy now and again :).