Would you let an 8-year-old have your credit card? Well, that's basically the situation when you let kids play with your iPhone or iPad. You see, 'in-app' purchasing has become the sneaky standard with 'freemium' app software. If you don't pay attention, you'll rack up hundreds of dollars from your kids trying out in-app software. Here is how you can prevent this unpleasant invoice experience...

_{(photo by Eternity in an Instant / Getty Images)}

Twitter is micro-blogging. Using short bursts of 140 characters or less, people share links, personal news,  local news, advice, and even philosophy. You follow people's  'tweets' for as long as they are interesting, and then unfollow them when they get boring. It's actually an interesting way to keep updated on your friends, your favorite celebrites, and knowledge gurus from around the world. About.com explains more about Twitter here...

Keyloggers are robot spies. Either employed by hackers, or by a suspicious spouse or parent, a keylogger trojan is a small bit of software that observes what you type on your keyboard. The trojan records your passwords, email text, and your private messaging. Theft, or punishment, will often follow next. About.com explains keylogger trojans here...

(photo by Iconica / Getty Images)

In online jargon, 'flaming' means attacking or insulting someone online. Someone who purposely posts mean public comments about you is known as a 'flamer'. If the flamer is a repeat offender who delights in attacking others, then we upgrade that person to being called a 'troll'. Read more about flaming and trolling here...

(photo by Foodpix / Getty Images)