Sugar on a Stick is the software originally available on the One Laptop Per Child project. Now it is separate. Walter Bender formed Sugar Labs to develop the Sugar educational interface and activity programs separated from the hardware development.
The big idea here is that SoaS makes one-to-one computing more viable. It does not need a fancy computer, just one that boots from USB (or can boot from CD with the extra ISO boot CD). The older computers being sidelined in schools can have longer life. The hard drive isn’t involved at all. Each student can have a complete learning system on a thumb drive. Prices locally (Boston, MA) for generic 8GB thumb drives have recently been around $8.00. That’s in single quantity. That’s affordable.
SoaS version 1 is now available. If you have not looked at it before because you didn’t have an OLPC, go through the steps to download the ISO image. At the very least, try it out on a regular PC by burning that image to CD. You can test the interface and find out about it. Then take the steps to make the USB thumb drive (minimum 1GB) which will let you go to any computer with a USB port and have a directory on the thumb drive to store your work.