Direct Price: Free
Requires: 400-MHz CPU; 128MB of RAM; 10MB of hard drive space; microphone; sound card; speakers or headphones; Internet connection; Microsoft Windows 2000 or XP
Company Info: Skype, www.skype.com

Built by the inventors of Kazaa, Skype lets you make free VoIP calls via your broadband connection. The service uses a peer-to-peer networking scheme, but rather than sharing files, connected PCs help route one another's calls. Skype also uses that routing technology to get around the need for (and cost of) central servers and directories, so call delivery can be free.

The software handles compression with several proprietary audio codecs, which, depending on the available bandwidth, deliver bit rates from 3 to 16 Kbps—enough for decent voice audio. The service does end-to-end encryption using 256-bit AES (Advanced Encryption Standard), which is nearly impossible to hack. Skype also supports text messaging, a useful feature for immediately sending notes to the other party.


We tested Version 0.93, a late beta, and found installation pretty easy. After you've downloaded and installed the software, a wizard walks you through registration, during which you set up your ID and password along with optional personal information. The first time we tried to register, Skype's server was down, but when we tried a few hours later, everything worked perfectly. The rest of the setup was a snap; the service worked without us having to adjust any router parameters. We weren't so lucky, though, with AOL Instant Messenger's Talk Feature, which we tried for comparison. AIM's talk feature doesn't work when two users are behind different firewalls.

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