I wasn't planning on posting this because it would have been useless with the release of 4.2.2 OS for the Pearl and it was looking imminent as discussed in previous threads but because I am sure there are others out there that can benefit from this now I decided to do a quick write-up.
First some disclaimers:
I don't believe this will have any impact on your airtime minutes and minimal impact on your data charges (if you are not on an unlimited plan) but I cannot be responsible if this method causes wierd charges or the disconnect is left open. I am a TMO customer using the Fave5 plan so even if it was racking up minutes I wouldn't notice.
Now for a few notes:
1. To use this method you will not be able to do other things on your device because it will rely on the device to be in a "transition mode" between connected on a call and disconnected from the call. So it is not perfect but for me when I am doing stuff around the house and want to listen to mp3s (will not work with video I don't think) it is a great solution.
2. I am not sure the quality of sound through this method as I listen to talk podcasts when I am using it and haven't really listened to music, although I have tried to make sure it works but have not listened intently for sound quality.
3. I don't know what this will do on Stereo BT Headphones like the S9 and Spider, etc. I have only tried with basic Motorola BT Headset. Report back if you try it with S9 or others.
Now for the steps:
1. Open Media Player and get it all set up to play the list of songs like you normally would using wired headphones (select the Play All, Play Folder or whatever works best but you will not be able to manually switch songs or even see the song list so make it a good mix for music folder) (Also, you will want to set it up to shuffle, repeat, etc as well at this point). The one thing you can do after you get it all set up is Pause the music because you will be able to switch between pause and play once connected to Bluetooth. Don't hit Stop though, just pause or use the Mute button to pause the music.
2. Turn on your Bluetooth device (if it is not already) and make sure it is connected to the device for making and receiving phone calls. You should see the Bluetooth symbol at the top of the screen with a couple arrows next to it to indicate it is connected. Also, make sure you don't have wired headphones or headsets attached to the device as this will override the Bluetooth functionality.
3. Open your browser and find a website with phone numbers to call on it. If you are in the US you can use the TMobile customer Care number by going to a web page I set up at the following location: BlackBerry BT MP3 Call Number
4. The phone number should be selectable in your browser. Scroll to the phone number and select click your trackball and you will get a message "Call [Number]", Select Call with the Trackball not the green call button and after it is starting to call the number hit the red "End Call" button. You will be left at a screen that says "Do you want to return to the Browser Session".
4. If you elected to pause the music before perfoming steps 3 and 4 you can press your Mute button to resume play and throughout the connection you can use Mute to toggle between "Play" and Pause". At this point you are what I have dubbed the "transition" state and the phone is still transmitting all sound to the Bluetooth device but you are not actually on a call. As soon as you get a call or select "Yes" or "No" or press just about any other key (except Mute) the sound will revert to your speaker.
I wish I could find the thread that this was mentioned in passing but I could not so if you posted this trick in that thread please identify yourself and Thank You from all that benefited from your trick and this post as well.