When I was about 6, I used to take my giant red original Game Boy, plug in a Game Genie, and put Super Mario Land in the top, turn on the codes for Walk Through All Walls, Infinite Lives, and Always Big Mario, and finish the entire game on the toilet.
Now, I'll usually just play a level or two of Sonic Rush Adventure (extremely underrated) or play some music on my phone. If I had my DS flashcard with me more often, I could read some stuff off of there, I guess.