PS3+external drive shared to PC

May have asked this here before but can't find a good answer on the net.

I know how to access files on my PC from the PS3 (use TVersity over wifi), but was wondering if I could access the files on my PS3 from my PC? Reverse sharing I suppose.
And then if I could plug an external HDD into the PS3 and get to those from my PC?

I think if you get an external HDD with a wifi built in then you could get PS3 to detect it, PS3 has bluetooth technology, a good way to hook up stuff wirelessly.

I haven't tried it before, but if I wanted stuff from my PC to PS3, I'd just copy the stuff onto my ext HDD and hook it up that way.

how does TVeristy work on PS3, is it any good?

Tversity is great for streaming PC content to PS3.

I want to do the reverse though, and can't find anything that says if I can or not (guessing not therefore)