I ended up helping one of the members set up Joomla on his local machine (Win XP) yesterday. So thought I'd share this with everyone

What you'll need:
- Joomla 1.0.x (meaning latest version in 1.0 series)
- Wamp5 grab it from http://www.wampserver.com/en/index.php
- Install Wamp
- unzip joomla into your wamp's www folder (eg C:\wamp\www\joomla
- start wamp
- open a browser window and go to http://localhost/joomla
- follow the on screen prompts to install joomla
- Host Name = localhost
- MySQL User Name = root
- MySQL Password = blank (don't put anything in this box)
- MySQL Database Name = anyhting you like (eg joomladb)
- MySQL Table Prefix = jos_ (this is set as default but you can change it)
- Make sure that install sample data is ticked
- Click "next"
- Site name = your site name
- VERY IMPORTANT!! Change the admin password to something memorable (as this is only for testing locally I'd suggest setting the password to admin or password or similar
- Remove or rename BOTH of the following: INSTALL.PHP and the installation folder (eg C:\wamp\www\joomla\installation\)
- in your browser window click on either the "view site" button or the "Administration" button
Discussion for this topic over here: http://forum.joomla.org/index.php/topic,88838.0.html