I link, therefore I am... citing Mark Amerika

As anyone who doesn't exclusively read the RSS feed knows, the description of this blog is a quote borrowed from MIT professor William Mitchell's book Me++ : The Cyborg Self and the Networked City.

This evening I got an e-mail:

the line in your header - "I link, therefore I am" - was originally used in the mid-90's by Mark Amerika in his hypertextural piece Grammatron.

Sure enough, those are the opening words, written almost a decade earlier.

A quick Google search suggests that lots of people have come up with the phrase. I wonder if one can find an earlier use than Amerika's?

[To the tune of Todd Rundgren, "Hello It's Me," from the album "Something/Anything? (Disc 2)".]