According to http://www.chillingeffects.org/trademark/faq:
Question: Can I use a trademark in my blog’s name or in the title of a blog post?
Answer: Yes, if it is relevant to the subject of your discussion and does not confuse people into thinking the trademark holder endorses your content. Courts have found that non-misleading use of trademarks in URLs and domain names of critical websites is fair. (Bally Total Fitness Holding Corp. v. Faber, URL http://www.compupix.com/ballysucks; Bosley Medical Institute v. Kremer, domain name http://www.bosleymedical.com). Companies can get particularly annoyed about these uses because they may make your post appear in search results relating to the company, but that doesn’t give them a right to stop you.
“Sometimes, you might use a trademark without even knowing someone claims it as a trademark. That is permitted as long as you’re not making commercial use in the same category of goods or services for which the trademark applies. Anyone can sell diesel fuel even though one company has trademarked DIESEL for jeans. Only holders of “famous” trademarks, like CocaCola, can stop use in all categories, but even they can’t block non-commercial uses of their marks.”