I've been using Calibre for a year now and love it. I was thinking about getting my son a book reader eventually (he's only 6 now), and started thinking I couldn't share my entire library with him (adult content). Not that he's going to want to read steamy romances, but anyway...

So I was thinking it might be nice to be able to password protect titles with some tags or a flag somewhere. Basically all titles with that tag would be hidden unless you turned them on with the password.

The other idea I was thinking of would be to have two libraries - one shared on the network that the whole family can see, and a personal one. It would be nice if Calibre could see more than one and let you pick which one to import books to.

Just some thoughts...would this be useful to anyone else?

I see where you are coming from since I am also a parent but I think that is a little impractical since the books themselves dont have ratings like movies, games, and music.
What I do is control the books on the reader by only loading the ones I want to have available (the ones that I deem appropriate) and all the others stay on my computer.

You can also have multiple libraries with calibre