Easily find your Facebook numeric personal ID/Application ID

For integrations of certain Facebook social plugins, like the "Like Button" and "Like Box", and others, Facebook requires that you know your Facebook numeric user ID.
Unfortunately, they make this very difficult to find, especially if you have a so-called "vanity" personalized profile URL.
If you can't find your Facebook ID, or don't know what it is and need it, just enter "Click Here" your full Facebook profile,page,group URL in the Box and click on "Lookup numeric ID"