[Technotroll]

In a lot of applications, there is no need to signal readiness. You can simply start processing the input at once, and display it continuously, from the first character or number that is entered. This is true for most applications that run client side. We're talking everything from small calculators to text processing. In most cases the "OK" button can be completely omitted. It's of course a different matter if you need to digest it remotely.