Wolfram|Alpha's long-term goal is to make all systematic knowledge immediately computable and accessible to everyone.
After trying it out a few times, it proved to be a valuable tool. For example, couple of weeks ago, my friends and I were talking about Y2K, the IT boom of the late 1990s and early 2000s. The topic of when is next IT boom (if there is one come) was inevitably brought up. Being a nerdy bunch, we all know about the limitation of time in a lot of computer systems. Since in a lot of system, time is defined as the number of second from the Epoch time (January 1 1970) where the storage mechanism is a 32-bit signed integer, it is fairly easy to see eventually, the number of seconds from Epoch will exceed a 32-bit signed integer.
So when is the exact time?
This is where Wolfram|Alpha comes in handy. Simply type in "1 January 1970 + (2^31-1) seconds" in their input text field.
So it is on January 19, 2038. That's still a long way away. Maybe all system would have moved to a 64-bit platform by then, or maybe not?