You will need to have all machines , PS3+PC+OTHER connected to each other either over a wireless network or wired .
Install PS3MEDIACENTRE on your PC , it will auto detect your PS3 and your PS3 will show PS3MEDIACENTRE in its media server file .
You can then browse all files (from your PS3) that is on your PC and external hardrive (if its hooked up to your PC) and play/view whatever you want from the PS3 that is on your PC /External .
Heres the best part.........
If you have a file type that PS3 does not support (ie) video , then you will notice that in your (eg) Movies folder you will see a folder named "TRANSCODER" ... in this folder you will also see all your movies ?? .... but when you play them from this folder it converts them whilst it streams them to your PS3 .
NO MORE LONG CONVERSIONS OF DIFFERENT MOVIE FILE TYPES . it converts as it streams .
Other great points to this software :
you can view all file types including .zip and .rar very handy !
It is a pimped version of MSMEDIA Player but the transcoding whilst streaming works straight out of the box .
I have no connections to the makers of this software , i just found it so painless to install and use and answered all my questions in one easy install .