written documentation of the proceedings of a party. (The party's "minutes", so to speak) Mainly includes profound words of wisdom spoken under the influence of whatever legal or illegal substances are present, such as "Where'd all these robes come from?" (Natasha, 3:25 a.m., 3/22/03)
As the night progresses and people become "sketchier", the term becomes increasingly relevant to the contents of the book.
Upon reviewing the book at a later time, if you are able to decipher your own scribbling, it can provide fabulous material for ridiculing the other partygoers for their wacky antics and genius-like wisdom.
Person 1: Wait, what? Wait, say that again so I can write it in the sketchbook...
Person 2: Ok... wait... was I talking just then?
During a night of drinking, the first friend to pass out then becomes a 'sketchbook' for all those in possession of a sharpie. This friend is subsequently photographed and posted to Facebook, thus becoming a Sketchbook Friend.
(adj) Hilarious way to describe a person, place, or thing as suspect, questionable, unsafe, dishonest, or disreputable. A play on words that nonsensically incorporates reference to cartoon character, Spongebob Squarepants.