Hi WannaBB,
It should allow running in the background already? Though you may be referring to what I'm about to talk about.
For AVRCP (and pretty much any control), the downside of the blackberry platform is there's no way for a third party (non-RIM) application to receive input events when it isn't in the foreground. So podtrapper will continue to play in the background but there's no way to control it (pause, ff, rewind, volume, etc) without bringing it to the foreground. My initial testing with AVRCP indicated that with that it's not even possible to capture those events when the application has the foreground. I've got it on my todo list to talk to RIM about it, but I haven't had an opportunity yet (still have plenty of other features to add and bugs to fix). It's definitely something I want to investigate, but I have a suspicion that it's simply not possible
Hope this answers your question, even if it's not the answer you (or I) want to hear. Unfortunately it's out of my control until RIM adds functionality to make it happen :/
-Marcus