Have you ever found yourself using someone elses PC, maybe at a cyber cafe, and found it just does not have the apps you want? Do you use OpenOffice at home and find it frustrating that you can't get that opensource goodness at work? Then PortableApps might just be for you...
First some background - a year or so ago I was messing about with Linux on a pendrive, and Firefox-on-a-stick. OpenOffice-on-a-stick was also under development at that time (not by me, I hasten to add).
At the time I could install what I liked at work, and none of my home machines will boot from USB, so it was all a bit of a fun curiosity, so things went a bit quiet..
Then the other day I was recommended this site, PortableApps.com by a friend, and very impressed I am too.
You can think of PortableApps as a wrapper that allows you to install a range of apps to, and run from, a USB drive. It comes in three variants. Base, which lets you install your own choice of apps, Lite, which comes with a range of apps including Amiword, and Standard, which replaces Amiword with OpenOffice suite.
Once installed on pretty much any USB mass storage device you run the PortableApps application from the pendrive and open the menu (left) from the icon that appears in your system tray. Choose your app, or add new ones from here.
Obviously, running from USB things are a bit slower than from HD, but even using my combination of a dirt-cheap SD card reader and generic SD card its perfectly usable. Installation of PortableApps was very slow however, so I suspect it really would justify the purchase of a decent device.
At time of writing 43 apps are available, including an AV package (useful!)and various backup solutions. So far it seems to be Windows only.
All-in-all its an extremely elegant solution to the problem of locked down machines.
I pair it on my stick with Damn Small Linux, for its 
ability to run its desktop within a Windows window, and the fact that it once managed to let me browse the web under Windows when no natively-running Windows browser could get at the web :)
