Since there are many versions of .Net Framework available ,it is very difficult to download and install each of them seperately.For maximum compatibility you must install all the .Net Frameworks from version 2.0 and above.The all in one installer released by Microsoft is 231 mb.However you can download an alternative AIO installer(for XP) of size 34mb.

Radical Image Optimization Tool (RIOT) is an amazing tool which can optimize and compress images without any noticeable loss in quality.This tool is extremely useful for Webmasters as it helps in faster loading of pages and in reducing bandwidth usage.

You can create a movie DVD containing a tiny bootable Linux Operating System-GeeXbox.This can play your movies,music on any computer irrespective of whether the computer has an installed operating system or not.
You just have to boot from the DVD media.

The GUI of VirtualBox does not have an option to boot a USB drive (Physical Drive) in a virtual machine.
However you can attach a physical drive to a virtual machine using a command line tool that is bundled with Virtual Box.You can then boot your virtual machine from the attached Physical drive.

Just like how you can boot a computer using a bootable CD,you can also boot a computer using a bootable USB drive.
You can test a bootable USB Drive within Windows without restarting your computer.This is helpful when your motherboard does not support booting from a USB Drive.