In the video below I will show you how to upgrade your Mac Mini from wireless 54g to Wireless N which will give you transfer rates up to about 135mbps instead of the traditional 54mbps. This will allow you to stream movies, move files, and much more quicker and easier on your wireless network.
Below is also the link to where I got the Wireless N card. I bought this card on ebay for about $26 with free shipping. I mentioned in the video that it looked like it was slightly used but worked great. You do not need any drivers. Once you upgrade it the Mac Mini will automatically install drivers for it, and if you are using bootcamp and have windows xp running it will also detect the drivers automatically. It is truly plug and play.
Here is the link to the ebay store I bought it from, please remember that I do not endorse this seller in anyway but I simply bought it here because of the price and that this seller has 99.6% positive feedback with over 5,200 sales that they have done. The product comes from Hong Kong, China and the shipping was not only free but arrived relatively quickly, it took about 2 weeks to get here.