A friend of mine has his PS3 connected to his computer and streams movies and tv series through it. It's really useful as his projector room is in a different floor than his computer. I think the program he uses to do this is called "Tversity".

I use PS3 media server, so I can stream files from my PC to PS3 it's very handy, for watching downloaded videos on a big screen.

I'm watching blu- ray movies on my PS3 until my standalone player arives.

" Uh, not really, dont put anything on the HDD.  The PS3 is a pain in the ass to use to stream stuff, the Xbox 360, basically having Media Center and being by MS makes it so much easier to stream music and videos.  Also the PS3 media search thing interferes with the internet connection. "

my dad is always showing guests, like family and stuff, photos on my HD tv using the ps3. and home videos too. 

no, but i plan on using it for a bluray player once i get some movies to buy. i can't find any good movies that are out/ coming out.

Nope, I only play games.

I use it with TVersity to stream all my videos from my PC so I can watch stuff in bed

I link my PS3 with Azureus on my PC, which is a torrent program. Because Azureus can transcode video files, there is no need to seek out specific file types that work with the PS3. Azureus can modify the file as needed so that it can be streamed on the PS3. Super easy.

I don't see the point of using up space for photos and videos while I could be using that space for games.. since it IS a playstation.

Sure. I use it frequently to listen to music.
My PS3 turns on alot faster than my PC, so when i need to relax, i'll go down to the basement, boot up my PS3, lay down on the couch, close my eyes, and listen to some Hollywood Undead.