Trying out Python 3 safely on Windows
Just a quick tip.
I wanted to try out Python 3 on my Windows machine without messing up my current Python 2.5 installation. Some rumors exist that it will change your .py file type associations, among other issues.
In order to prevent this from happening, there are 2 simple steps.
Make sure the installation path isn't the same as your current Python installation path to avoid overriding it:

Make sure the option to "Register Extensions" is disabled in order to preserve your file type associations and leave your previous Python installation as default:

So far I haven't had any problems with this setup, so happy Py3K'ing!
