This week, Skype, the voice and video chat application, announced Skype in the Classroom, a free service to help teachers connect their classrooms with other classrooms around the world. With 4800 teachers already signed up, teachers can find partner classrooms by searching geographically or by project. Project postings summarize the kind of interaction teachers are looking for, and can be filtered by age, language, subject or type.

TeamViewer is an all-in-one solution for remote access and shared- screen online meetings. And it is free for non-commercial users. Which means you can use it to troubleshoot Grandma’s computer problems from the comfort of your own computer, whether you use Mac, Windows, Linux or even an iPhone. Use it to collaborate with family members when creating a family photo album, or in a classroom for educational purposes.

Just in time for Halloween, this week’s tip exposes a zombie network you may have seen in airports and hotel lobbies across the country: Free Public Wifi. There is actually nothing free, public or even Wifi about this network. It is a rouge, default network that is spread from computer to computer, thanks to an old Windows XP bug. When selected, you will not be able to access the Internet, but you could be exposing your computer to a clever hacker. To learn more about how Free Public Wifi has spread and why it’s become so rampant, read National Public Radio.

When using a public wi-fi network in an Internet café or coffee house, it is up to you to secure your transmissions against prying eyes. Only using https secure connections is one way of stopping those around you from seeing your transmissions. For more cyber café security tips, read Ask Leo, and PC Magazine.

Wikipedia is a collaboratively-edited encyclopedia, but only a small percentage of visitors ever contribute by editing an article. To learn how, start with this overview from Gina Trapani or the official Wikipedia Tutorial And if you think that the tutorial itself needs improvement, feel free to jump in and add your own two cents.

Cable clutter is the bane of the modern desk. This tip from the Closet Entrepreneur offers instruction on how to use a simple daisy chain (or chain sinnet) to tame stray cables and power cords. The article includes a video that shows a slightly different method for long extension cords.

Free Wi-Fi hotspots can usually be found at public libraries, Barnes & Noble and McDonald’s. But there is no reason to limit yourself to these well-known spots. In her “Definitive Guide to Finding Free Wi-Fi” Gina Trapini lists free tools for Windows, Mac and smartphones for finding public hotspots wherever you may roam.

There are many Internet speed tests that will measure your download and upload speeds. Speedtest.net, CNET Bandwidth Meter Speed Test and PC Pitstop are a few. But before using them, you need to understand terms such as “k”, “m”, “bits” and “bytes.” For that, I recommend reading Ask-Leo.

Looking for a simple way to occasionally share files between your computer at home and one at work? Google Desktop 3 has an optional “Search Across Computers” feature that may be just what you need. Although some have raised privacy concerns, Developer Shed at Search Engine News concludes it is a useful tool that can be controlled . Learn more at Search Engine News and at Google Desktop.

Securing a wireless home network consists of several steps. First change the default password (which you can find online at http://www.routerpasswords.com/ ), then change the router’s default name, then add encryption. For a step-by-step illustrated guide, read CNET’s How to Secure Your Home Network.