PortableApps is a portable application platform. I use it everyday. There are a lot of applications out there, many of them free and capable of running from a USB memory stick.  Three years ago I set out to make the ultimate USB drive, not just with applications, but full servers and other useful tools and methods of organization. Today, I use free portable applications for pretty much everything I do from browsing the web to running a full web server. PortableApps.com has made this much easier. Although I have some applications that they don’t yet, I look forward to when they do. It’s nice to have a central place to find portable applications, rather than trying to make them all portable on your own. It’s also extremely stable, I’ve been running this platform for well over a year, and haven’t had to rebuild it at all.