My iPhone is causing crazy interference if I get it near any speakers. What's going on?

If I get this little gadget within 2 feet of any computer, speakers, TV, or even another phone, the speakers on those things buzz and hiss. What in the world is my phone emitting, and how do I make it stop?? It's jailbroken with redsn0w on 3.0.1, and I believe I have wifi, bluetooth, SSH, edge, and 3G all... show more If I get this little gadget within 2 feet of any computer, speakers, TV, or even another phone, the speakers on those things buzz and hiss. What in the world is my phone emitting, and how do I make it stop??

It's jailbroken with redsn0w on 3.0.1, and I believe I have wifi, bluetooth, SSH, edge, and 3G all turned off. I find SBSprefs harder to navigate than good 'ol bossprefs, though, so I'm not sure. It's only mercifully quiet if I stick it in the center of the room alone or put it in airplane mode. This thing is first and foremost a phone, so I'd rather not do that!
Update: It wasn't nearly as bad before I updated to 3.0.1. :(
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