I'm not sure if everyone knows this, but Windows Media Player 11 has a compatible DLNA server built into it which is extremely simple to use:
- launch Windows Media Player 11
- go to Tools... Options... Library
- click Configure Sharing
- click Share my media... click OK
A Media Sharing window appears. If your PS3 is on, logged in and attached to your network it should appear here (as Unknown Device).
On your PS3 just go to Videos or Music and at the top of the list you should see your PC's name. Click on that and browse your shared media!
To choose which files and folders are shared, simply click (in Windows Media Player) the Monitor Folders button (it is located on the same screen you clicked Configure Sharing).
Now a great feature of this sharing isn't just that you can play music and videos off your PC, but you can also copy the files directly to your PS3! Press the Triangle button on a media file to find the copy options (use Copy Multiple if you want to copy more than one!).
Also, when using this method to copy to your PS3's HDD you don't have to worry about file sizes. I was able to copy over several high def movies, some of which are over 12GB in size!
Finally a use for that 500GB HDD upgrade I did nearly a year ago lol!