Ask HN: Is this a feasible business idea?

A couple weeks ago I had an idea for a new service, but I'm not sure it's something others would find useful or if it would be accepted as an authority.

Basically, what I'm thinking is a service where people could do things like store notes, pictures, recordings, etc. and each item would be stored in such a way so that it could not be later altered (was thinking MySQL archive tables).

For example, the idea came to mind when my wife moved out a few weeks ago. Every time we have a conversation I feel like I need to document it, e.g. "Just spoke with X and stated that abc" and have that stored on a server of a non-biased company somewhere so that if the situation gets to the point of legal counsel being brought in I could put together a sort of log or journal of what's been said and when.

If this was something that could be useful, I could build out mobile apps that could take recordings and submit those or even automatically forward text messages from selected individuals. I would, of course, want something like triple redundancy on the databases to ensure nothing is lost.

But, like I said earlier, I'm not sure such a service would be helpful to others or if lawyers/courts would even consider the information worthwhile or admissible.

What say ye, all wise HN community? :)