6. Every Extend Extra (PSP)
The only thing you'll be extending is your bathroom time with this bizarrely addictive UMD. And when we say "extend," we mean turds so lengthy, a Special Ops agent could use them to rappel down the side of a building.
Recommended Dose: When you reach a boss, it's time to reach for T.P.

5. Lumines & Lumines II (PSP)
This PSP puzzler proved to be so addictive that gamers were bringing the game into the outhouse with them. Once there, they found themselves so entranced by the game's techno soundtrack and square-matching action that they not only shat out all their Whoppers, Doritos, and undigested red meat, but they also completely lost track of time. Upon finally leaving the outhouse, they emerged to discover that: 1. they now had Rip Van Winkle–type beards, and 2. the world had been destroyed by either nuclear war or that tentacled thing in Cloverfield.
Recommended Dose: One round per john visit.

4. Phase (iPod)
This music-gaming hybrid from Harmonix, makers of Rock Band and the original Guitar Hero games, lets you synch your personal playlist with a simplistic, but completely addictive, video game. Spin your iPod's click wheel in time with the music, gain multipliers, and earn high scores, all while squeezing out last night's rectum-scorching beer crap.
Recommended Dose: Three songs or less per squat. Unless one of the songs happens to be "Stairway to Heaven." Then, and only then, one song will do.

3. Tiger Woods PGA Tour 08 (DS/PSP)
Picture it: The back nine at Pebble Beach. Virtual waves crashing against the shoreline. A seabird cries from the nearby stand of trees. If this soothing setting doesn't cause your rectum to dilate, nothing will.
Recommended Dose: Play a hole each time you crap. One round of golf = 18 shits.

2. Wipeout Pulse (PSP)
We'll state the obvious: It was the word "wipe" that originally made us haul this UMD into the john with us. But what made it a john staple was not the high-speed futuristic racing action, but the game's weapons—especially that juice-sapping Energy Drawer (it saps the energy from your opponent while refilling your own tank). Warning: Draining someone's shields to nil then ramming into them until they explode may cause intense involuntary crowning.
Recommended Dose: Run a single race of three laps or less per bowel evacuation.

1. Tetris DS (DS)
Five words: "Come on, long skinny one!"
Recommended Dose: One round per dump. Unless you're a Tetris pro and your rounds last more than 10 minutes. Because four out of five doctors agree that sitting on the toilet for more than 10 minutes can cause damage to your sphincter. And five out of five doctors agree that staying in the bathroom for more than 10 minutes can raise suspicion that you are not crapping at all, but enjoying a bout of high-speed self-pleasure.