1. Crack fingers loudly. Over and over again.
2. Cough, sneeze. Over and over again.
3. Groan and moan. Think Bubonic.
4. Start crying.
5. Talk on your cell, even if it's to nobody.
6. Crush your water bottles in a loud, offensive manner.
7. Start undressing. Don't stop until the perpetrator leaves. Or asks for your number.
9. Mutter to yourself incessantly.
10. Pick your nose and flick the boogers.
I find myself in these situations time and time again, and these tactics have yet to fail. With especially hard cases, employ a combinational approach. Tactic 4 has proven especially effective. Remember, if at first you don't succeed, cry, cry again.