How do I casually eavesdrop on other conversations without being obvious?

Eavesdropping is an activity that humans have practiced long before anything important was ever said. After people realized that they can use this overheard information for spying or amusement, it became hard to resist the urge of listening to strangers gossip about people who you will most likely never meet. While eavesdropping can be fun, obviously participating in such a timeless act without utilizing the proper stealth and espionage involved in eavesdropping can lead to awkwardness, violence, adult situations, drug use and fantasy violence.

Surprisingly, people do not like to be listened to by an outside party. Furthermore, they do not like to be watched from any sort of distance, nor smelled or rubbed up on while riding the bus. Though these things will forever be part of the mystery that is mankind, it is something you should definitely account for. Do not make grand gestures that remove doubt that you are eavesdropping. At the very least, do not use an old-timey ear-horn pointed directly at the table next to you. If you want to passively spy more effectively, here are some quick "eaves" you can "drop" on. (I don't know what that means. Wordplay confuses and scares me.)

1.) Headphones Heads-up - Since we live in a wonderland of technology, headphones are easy to come by. With a pair of these badboys, you do not even need an MP3 player to offer some entertainment. Simply have the cord coming from your pocket or book-bag, and everyone will assume you are jamming to some Pat Boone, and not learning about how the one time they and Jim got drunk and totally hooked up, but it was really odd because Jim is their pet ferret.

(Note: do not use noise cancellation headphones. They are not meant for this.)

2.) Look Occupied - Try to have something around you that you must constantly attend to. If you are at a coffee shop, constantly stir more sugar into your coffee. Look like you are really into that day's crossword puzzle, even if you don't know what 33 letter website is "a modern day Plato's 'The Republic" (we'll give you a hint: it rhymes with ble blurvival bluide blo bleveryblay blife. blom). If you are on the bus, try smelling and rubbing up on people.

3.) Do not become attached - Everyone on the field of eavesdropping is told one truth about living this lifestyle, and that is to never fall in love. If you happen to find yourself completely taken by someone, you cannot follow them, or use information obtained in your eavesdropping as to where they are going to be later (it's like how evidence can't be used in court if it was obtained without a warrant, only with more emphasis on social respectability and not being a creepjob). This helps you not become a stalker and avoid the pitfalls of stalking like thornbushes and locks.