"The Tube" was made up by Brandon DiCamillo, who frequently talks about it on Radio Bam. The Tube is a long, clear plastic tube. It is used in a competition where two people, preferably men, insert an end into each of their anuses. Then they both defecate. The winner is determined by whose feces comes out the other side.
Phrase meaning - Fully reachable through on-line chat, email, and phone. Typically used in an collaborative work setting to denote that you will be out of office, but easily reachable. Originating in the southeast, it may be a derivation stemming from the old office mail suction tubes - "able to be reached through the tubes".