@

The at symbol (or @) on your keyboard is made by pressing the Shift key and the number 2 at the same time.

Real Life Usage

These are examples of where the at sign is used in real life.

• Twitter, the usernames are always followed by @.
• IRC, in some IRC networks, your nick name is followed by @.
• Email addresses, the @ symbol is commonly used in email address formatting.
• Emoticons, sometimes the @ symbol is used in emoticons, such as @_@. Hackers think they're cool for using these.
• Insults, sometimes used when calling somebody a tw@ (twat), which is a slang for a vagina.
• Replying, this is frequently used when replying to someone, either on a forum, or some other messageboard site that doesn't have a quoting system. For example, somebody might say @shitposter... and then write their message.
• Laziness, some people might use this because they're simply too lazy to type the full two-letter word.