Astaro's new free software gives you an excellent way to reuse your old P4 computer. Instead of just tossing it away, Astaro's Security Gateway Version 8 Home Edition can turn your P4 into a killer security gateway with effective network-level malware blocking, a powerful firewall, and a content-based URL filter.

To use Astaro you'll need a Pentium 4 processor at 1.5 GHz, 1GB of RAM, a 20GB hard drive, a bootable CD-ROM and two network interface cards. Note, though: You'll need serious network skills to manage installation and configuration. Read our full review of Astaro Security Gateway Version 8 Home Edition at PCMag.com.