There are a lot of converging ideas out there, for "self-hosted NSA of yourself" type software which gather your own data from services you use and index it / make it more accessible to users. Would love to see something serious come out of it.

I followed Timeliner early on and really like the idea, but yeah it's a bitch to get traction for this sort of thing. You need people willing to implement backends for basically everything, then maintain them.