Like any meditation worth the webpage it’s written on, this one can be done anywhere, at any time, whether sitting on a zafu with Nag Champa burning in the incense bowl, or running down Concourse C to catch your connecting flight:
Search all of your experience in an attempt to find the edge, the border between consciousness and the rest of the world, between consciousness and that-which-is-not-consciousness. Find where this appearance ends.
Look everywhere. Use every sense. Focus broadly but intently. Look for anywhere in what is that is not absolutely bursting with intimate, indescribable experience.
One nice side effect of this meditation is that it is impossible to be bored while you’re doing it, so if you’ve got any long bus or plane rides coming up, bookmark this page.