So it's Friday afternoon, the weekend is just around the corner, and you're up to no good. Rather than waste your time turning monitors upside down around the office, why not update your tech arsenal? If you have a computer or cell phone on hand, you're more than ready to beef up your weapons and spy kit with these 12 sly tricks. We'll teach you why and how (and with what) to do them, and tell you how well you can expect them to work. And you will forget where you heard this information...

Turn Wi-Fi Thieves' Worlds Upside Down

The problem: You took the time and expense to set up a wireless Internet connection at your place. But you're pretty sure that the cheap bastard next door is stealing it--that is, connecting to the Internet on your dime. Sure, you could take the easy step of password-protecting your network, but what fun is settling for a little common-sense measure like that?

The trick: With the help of a lovely little service called Upside-Down-Ternet, you can turn that Wi-Fi thief's free Internet scheme upside down--literally. With a little clever scripting, every image the thief views via your connection is flipped upside down on his monitor and mirrored, making Web browsing difficult to say the least. You can also redirect every Web request the thief makes to a particular site--the author of the hack suggests Kittenwar. Pretty good, but I would go with an old standby.

The effect: The trick takes a little work to set up right, but if you can pull it off, it works perfectly. And doing right by one's neighbor just makes you feel good inside.

Never Be 'Away' With Your AIM Bot

The problem: Some employers use IM clients to track their workers and ensure they're keeping their noses to the grindstone--but, hey, you don't like Big Brother staring over your shoulder.

The trick: Create your own AIM bot with the Web site RunABot. An AIM bot is an automated chat robot that resembles any other AIM user, and--if you set it up well--it responds to messages like a real person. Once you register with RunABot, the site walks you through setting up your bare-bones bot; then it's up to you to make your bot believable.

The effect: In the time it takes to customize your bot to fool your boss in all situations, you could probably finish several work projects and earn a few promotions. With just a few minutes of setup time, however, the "hardworker" bot I put together can convincingly participate in simple workplace conversations.

Make a Laptop Thief Regret It

The problem: Every time you leave your table at the bookstore for another cup of coffee, you've got to choose what to do with your laptop. You'll only be gone for a few seconds, so lugging it with you is a pain. Still, the guy with a double espresso has been eyeing your gear since you sat down, and he looks like he could have sticky fingers.

The trick: Install an antitheft program on your laptop that monitors unusual behavior when you're away, setting off an alarm whenever it detects a possible theft. The freeware Windows application Laptop Alarm sounds an alarm whenever your laptop's power cable is unplugged, the mouse is moved, or the laptop is shut down. Mac users should check out iAlertU, a freeware app that uses your MacBook's built-in accelerometer to set off the alarm and snag a Webcam picture whenever someone so much as moves your laptop. You can smoothly disable the alarm with your Apple remote like a proper car alarm.

The effect: Under the right circumstances, these applications can be enough to deter a thief from running off with your laptop. Neither application is foolproof, however: Don't consider these apps as anything more than deterrents.