Nice idea for a thread, charon9. I like it. Maybe we can use it to post ongoing content tips.
The press kits from the manufacturer are a great resource for high-res photos. I also use Google Image Search quite often to get at those hard-to-find images. I make sure to look at the image resolutions posted in the results. You really have to be careful that you're finding the correct image, in a decent size.
Tech Specs / Features
I really believe the job of ProductWiki is to distill and filter the information out there. While, most manufacturers will post detailed specs on a product, it takes a keen eye and some a priori knowledge to extract out the meaningful numbers. For example, in the receiver/amplifier world, mfgrs often report power in Watts per channel, but they often don't state if it's peak or dynamic power, or whether or not the power rating applies if all speakers are being driven at the same power. To me, it's more important to be succinct than thorough.