1.) ...you're caught listening to the extended version of "Blue Monday".
2.) ...you check your email box to find it empty, then check it again.
3.) ...you attempt to sing Backstreet Boys lyrics.
4.) ...you make up and do your own homework.
5.) ...you set up a two player match on Halo and make it constantly jump off a cliff for target practice.
6.) ...if you chase around small animals with a weed eater.
7.) ...if you practice belt whipping.
8.) ...if you surf through 223 TV Stations to find nothing on, then scan through them again backwards.
9A.) ...if you listen to Opera.
9B.) ...if you watch Operah.
10.) ...if you sit and stare at the SETI Program.
11.) ...if you sit and make your own list of movie credits for your fake movie.
12.) ...if you're caught singing the chorus to "Louie Louie".
13.) ...if you stare at you Discussion Boards Index.
14.) ...if you toss pennies into a Cowboy Hat.
15.) ...if you replay your game consoles intro constantly.
16.) ...if you start a thread about it.
17.) ...maintain a blog
18.) ...practice ninja shadow fighting
19.) ...see how long you can hold your breath
20.) ...listen to powerman5k
Thanks to John Nada and Lysergic for 16 through 20.