1. The Phony Phone Message
Find the number for your nearest zoo. Give your colleague a message to call and ask to speak with Mrs. C Lyon.
2. Suspect Signature
Change a colleague's email signature to read "Lots of love and hugs, [Their Name]."
3. Noise Pollution
Hide a wireless doorbell in your colleague's office/cubicle/desk. Keep ringing it.
4. New Folder
Make your colleague a new folder on his or her desktop. Label it for maximum embarrassment. "My Nudey Pics" works well.
5. The Coin Trick
Stick a coin to the floor in a busy area of your workplace. See how many people bend down to pick it up.
6. Remote Control
Get a wireless mouse with a tiny USB receiver and plug it into your colleague's computer. Give the mouse a wiggle every now and then.
7. Heavy Handset
Find some double-sided sticky tape. Tape your colleague's phone handset down to the base. Dial his number and watch as the entire phone lifts up when he answers.
8. Wrong Number
Collaborate with colleagues to phone your victim repeatedly asking for "Bill." At the end of the day, get someone to call pretending to be Bill asking if there are any messages for him.
9. Sticky Pens
Super glue your colleague's pens to her desk. It's simple, but very effective.
10. Bieber Fever
Finally, why not "decorate" a colleague's office/cubicle/desk with images of The Bieb? They'll secretly love it.