During my time at University, I have come across many useful tools available in Linux that are not available in Windows. I know what some of you are thinking. I could simply switch to Linux, as it is more-or-less as easy to use as Windows. But I require some programming tools in Windows that make the switch impossible. I really did not want to reboot every time I required a Linux-only program. For a long time I would use a VNC client to remotely log into a Linux PC to use the tools I needed, but that left me with two locations with current files. Not ideal.
I first started to use Cygwin to make the tools I needed available, while I was running the Windows programs I liked, or needed. This worked well, but it is a little tricky to set up and it frustrated me that I was limited to the programs that Cygwin supported (these were often not the latest versions).
After trying virtual machines and a brief stint with andLinux (also quite nice), I have now found an easy way of using Linux programs in Windows. Portable Ubuntu is a distribution that, like andLinux, is based on the coLinux kernel. It allows you to use Ubuntu 8.04LTS while you are booted into Windows. Another major advantage is that, like the name suggests, the folder created by the installation file is portable. You can simply copy it to a flash disk or another PC and have the same functionality where ever you go. You can easily reach your files on the C drive via /mnt/C/. When you run the program, you end up with a small task bar that you can move as you wish. If you somehow manage to break it, you simply delete the folder and start from scratch. It is really easy and does not leave any traces on your Windows drive.
Draptik has written a easy-to-follow articles on how to upgrade Portable Ubuntu to v8.10 and how to access other partitions. I suggest you read them. Increasing the size of the default disk image is almost a must.
Update: The project is now called Portable Ubuntu Remix and is in version DOS (as in Spanish for 2, not the Microsoft product). It is currently in Release 4 and runs Ubuntu 9.04 with updated Colinux and Cygwin. There is a lite version available (now in Release 2) which creates with a smaller disk image (2GB vs 3.7GB) without the office, media, graphics and Gnome themes.
I have not tried it yet as my version UNO with a larger partition and upgraded to 9.04 is working smoothly and I cannot afford to have problems with a new install at the moment.