1. pg-bot technology for responding on holidays to posts about funding. The bot should have sufficient business sense for pointing young entrepreneurs in the right direction, but should also contain semantic sense for responding in a witty and lighthearted way... for example, in Haiku.
idea 1 = reel to reel tape
idea 2 = self contained cassettes
idea 3 = hard disks
idea 4 = floppy disks
idea 5 = flash based drives
If you concentrate on the problem (we build the most reliable/fastest/cheapest devices for persistent storage) instead of the idea (we build the most reliable/fastest/cheapest tape drives) then you're less likely to be screwed when the market or technology changes
The benefit to targeting a "problem" is that you have a preexisting need. An "idea" with no existing "problem" may require several years of extra lead-in where you are struggling to get people to understand what you do and why it should matter to them. It can work, but the ratios are less favorable for a VC-style investment which looks for fast turnaround with minimal risk and orders-of-magnitude payoff.
But the key is to always have a set of problems floating in your head. Having an idea, and seeing what problems that idea can solve is not as effective, as you often end up trying to force a square into a hole.