James asks, "What's the best way to get your foot in the door with a company to be able to test their hardware or software?"
Well, it's quite easy with a lot of companies, just ask their sales division to be put in contact with the right people... Most companies don't openly search out for new testers, instead, they wait for them to show interest. Some companies these days will approach users with worthwhile reviews on Amazon to do testing in exchange for a review.
Hewlett Packard as an example, has a beta testing site here
which is powered by VOC Online
which is itself a large beta testing site.
Regardless of how you get your foot in the door, you'll need to have solid reasons that you'll need to share on WHY you want to be a part of a product testing group; a simple reason is that you want to test how the products work in your environment and would like to help with the product documentation...