Please see this information about fair use. It explains well all the things you need to consider before using other people's images in your blog. Scroll down to the section called Fair Use to see more. Using an image from a company's website seems to be fair use as long as the words about it are your own, you link back to the site/give credit to the copyright owner, and do not copy a substantial amount of the product website for fair use onto your own website.
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Creative Common Search is a search portal that offers convenient access to search services provided by other independent search services. From this one site you can link to Google Images, Flickr, Fotopedia, Wikimedia Commons and other media sites. Do not assume that all images found on the independent sites will fall under CC license.