Clark was recently disturbed to learn that your personal info can float out in cyberspace long after you think it has been removed. This is because of caching issues.

Search engines send spiders out across the web to find info that's stored on servers all over the world. Then they present that info to you during a web search.

But the spiders only crawl certain parts of the web every few days or weeks. So info can be stored or "cached" in cyberspace even after it's gone from the original server. In most cases, there will be a lag before it disappears completely.

When it comes to browser security, Clark uses a free tool available at Finjan.com. It prevents him from going to mistyped addresses where danger may lurk, and it goes beyond just looking at URLs to look at the actual code on a page.

Meanwhile, here's one low-tech suggestion to beat keyloggers. A keylogger is a program that gets secretly installed on your computer when you visit bogus websites. It can be used to track every keystroke you make and steal valuable passwords.

This trick involves typing passwords out of order or adding extra characters that you goes back and erases before logging on. Say for example your password is "jane." Instead of typing "j-a-n-e," try typing something like "j-a-x-n-x-e." Then go back and manually erase the extra characters (the x's) using your mouse, not the keyboard, and you just may trick someone who may be remotely monitoring your keystrokes!

RIP-OFF ALERT: Clark recently spoke about protecting yourself online against cyber-criminals. Now technology columnist Walt Mossberg has compiled a handy list that reinforces the message. Below are some excerpts:

• Never click on a link in an e-mail that appears to be from your bank, credit union or brokerage. Call the company if you are in doubt.
• Don't click on links in an e-mail offering free goods or services.
• Never download free software from unknown websites.
• Don't download video drivers from sites other than Microsoft, Adobe or Apple.

Clark also wants to add that you should be using a browser like Firefox, which is safer than Internet Explorer. Please note that it's OK to download new security patches from Firefox.

People have been asking Clark about that website he recently discussed that blocks suspect sites from loading in your browser. It's HauteSecure.com.

Finally, Mossberg also recommends a free service from McAfee called Site Advisor that alerts you when a web address could be dangerous.

Clark loves free services and has 2 new ones to share with you. The first comes from a company called HauteSecure.com, which protects your computer if you mistype a web address. Too often criminals will register bogus domains that may be just one letter off from a legitimate address. When you hit those fake sites, your computer may become infected with a keylogger program. So the free download at HauteSecure.com protects you by blocking sites that could threaten your computer.

The second service Clark has discovered is called ChaCha.com. This free mobile phone service allows you to ask a question by calling 800-2-CHA-CHA. You then receive a text with your answer. It's like Google for your cell phone. So far the results have been hit or miss. While it worked well during a pre-show meeting, it returned a wrong answer when Clark tried it out on air by asking, "Who won the 1964 World Series?" He received a dud answer via text message -- The New York Yankees -- in about half an hour. It was the St. Louis Cardinals who beat the Yanks in 7 games!

RIP-OFF ALERT: Have you been enticed on the Internet with offers of free iPods, free computers, free flat-screen TVs and free vacations? If so, don't click through on those pop-ups or banner ads! Online marketer ValueClick has been fined $3 million for ripping people off with these kinds of false Internet come-ons. If you did click through on such ads, you'd have to navigate through multiple screens of sales pitches and surveys. Some people fell for the promise of free goodies and purchased what was being sold -- all in the hopes that it might improve their chances of getting that free iPod or free vacation.

Clark's producer Kim admits to having clicked through on these kinds of ads when she was enticed by an offer of an advance DVD copy of the third season of ABC's Lost. She clicked through multiple screens for about 15 minutes and eventually just closed out of her browser in frustration. Pop-up blockers have really helped to minimize the intrusion of these kinds of ads. But there are still embedded banner ads that tout this kind of stuff. Just before Christmas, the very popular Nintendo Wii seemed to be the product of choice for the scammers to promise you. Just know this: When somebody touts something for free, it's probably anything but that.

An old, but evil scam is back bigger than ever, according to a report in the St. Petersburg Times. It targets people on the Internet who use a dial-up connection. DSL and cable subscribers are not affected. What happens is you’re surfing at home, and a pop-up appears. You try to click out of it, but you don’t quite hit the “X.” And when you’re not at home or on the computer, or when you’re asleep, a dialer program takes over your telephone line and makes calls to places you’ve never heard of. Your phone has been hijacked. Unfortunately, the phone industry has taken the position that you are responsible for the charges. That is ridiculous. There is a lot of gray matter when it comes to resolving these issues. The industry knows all about it, but many companies claim they don’t know anything about it. Verizon is at least notifying customers that it is going on. But, the only solution is to get “international call block” on your phone if you have no need to make international calls. Even if you need to make international calls, Clark has ways other than dialing “011” first on his site. Click here for more. You can also block pop-ups from appearing on your screen in the first place. On Clark’s site, we have information listed about this. Or Clark is fond of the toolbar.google.com.

Clark can’t stand pop-up ads, those annoying ads that suddenly appear on your screen while you’re trying to surf the Web. They were originally an AOL invention, and AOL used to pop these ads up all the time. Thankfully, AOL has reduced the number of pop-ups it sends out because so many customers have complained. There are pop-up programs out there such as the one from google.com, which you can find at toolbar.google.com. Well, there is a new form of pop-up coming our way. Companies will now start bombarding you with full-screen television commercials while you’re online, according to the New York Times. The 30-second commercials will be downloaded while you surf. And, when you go to a new page, the commercial loads and covers the entire screen. Even if you have a slow Internet connection, the movie will still play. So far, Pepsi, AT&T, Honda, Vonage and Warner Brothers will be sending out these ads. Clark thinks people should have the option of seeing these ads. It’s fine to charge for content, as Fortune, Business Week, and the Wall Street Journal all do. But Clark thinks people should get something in return for watching these ads. For instance, people should be able to get free content for watching ads. If you don’t watch the ads, you must pay.