I get to see a lot of startup ideas these days, mostly thanks to AngelList and the conferences I attend. I have noticed a significant trend that is understandable but troubling. We seem to be running low on truly original ideas.
Almost every startup describes themselves as the "[Hot Company] for [Big Market]", or "like [Hot Company 1] meets [Hot Company 2] and [Hot Company 3]". This is, of course, somewhat natural, as it helps your audience understand what you are doing if you can "anchor" it to known concepts.
But I can't help but wonder how Twitter described themselves. Of course, they did not have to go out and raise money in their early days, since it was built out of the ashes of Odeo.
I am a big fan of things that take an offline process and put in online, adding efficiency and utility to the process. So I like to hear comparisons to brick and mortar companies or processes. This also makes it more likely that you are not asking the carbon-based windbags who you hope will eventually give you money to materially change their behavior.