Use a Jailbroken iPhone/iTouch to create a music media server for your ps3 on a shared wifi connection.

[2legit2quit]

What you will need:

-PS3
-IPHONE/ITOUCH that is jailbroken (ive been testing this on my i4 on 4.1 FW) Should work with older models...
-WIFI CONNECTION
-Safari Download Manager
-iFile



1. Search and install "itunesdb" on cydia (this program originally comes with a 15 min trial, then you have to pay 10 EUROs for the full version, Here's a crack
2. Download this zip on your computer/or/idevice http://www.multiupload.com/HQO9MX0PI9

If the .zip has been downloaded on a Computer: Copy and overwrite these locations within the idevice's root file system,
Copy and overwrite upnpAVServerd to /usr/bin
Copy and overwrite ITunesdbUPnPAVServer_ to /Applications/uPnPAVServer.app
Reboot
DONE, Patch Applied

If downloaded through Safari Download Manager (on idevice):
Nav to var/mobile/media/downloads
use ifile's unarchiver to unzip folder
Cut/paste files from within ifile:
upnpAVServerd to /usr/bin
ITunesdbUPnPAVServer_ to /Applications/uPnPAVServer.app
Delete existing files in those directories and replace with patched ones
Reboot
DONE, Patch Applied

CRACKED BY MEGATRON <---Thanks

Now your ready to setup a media server with the PS3.
Connect your PS3 and idevice to the same WIFI NETWORK.
On your iDevice run the itunesdb app and start the server controller
On the playstation, nav to your music section and search for media servers or wait for the ps3 to auto detect within that section.
After the PS3 finds the server, connect and your music library will be viewable within the XMB
Now you can nav through your itunes playlists on your PS3 wirelessly and copy your music data from your iDevice to the Playstation's HDD.

NOTE: This program works decent at the best of times, its has some minor bugs. Overall, it gets the job done when streaming music/copying files.
Enjoy

[2legit2quit]

UPDATE*
This method is confirmed working on my iPhone 4 (iOS 4.3.3-RedSn0w) and 3.61 OFW

[ichibaka]

cumbersome... better to just find an app to rip music directly from iphone to pc. I'm sorry but music without equalizer just sounds shitty to the ear, especially lossless mp3, even if it's digital.