Apple's Steve Jobs unveiled its new iPhone at MacWorld 2007 this week. As a result, Cisco as promptly filed a lawsuit against Apple for trademark infringement. You can read more from Cisco's blog.
I personally find the entire spectacle humoring. No one has ever heard of Cisco's iPhone. On the other hand, everyone understands and equates Apple's iNoun name with their product lines. I see no misunderstanding between the two product; which are totally different.
It will be interesting to see how this plays out by the June 2007 launch.