Twitter seems to be going strong, despite early questions about whether it would ever shed the notion of being a waste of time, as evidenced by this currently running billboard ad:
To the extent this billboard looks familiar (admittedly a more diminutive glass here), you might recall my questions about it three years ago: Marketing Nirvana for Twitter?
Kyle did a pretty solid job of answering those questions, do you agree with his assessment?
Here are a few more: Is it time for a new Summit billboard ad? Does Summit only buy billboard ad space obstructed by power-lines?
For other possible examples of nominative fair use, check them out here.