Like many of you, I too had some crackling and staticky sounds with my pa1mOne hybrid stereo headset. Here's what I did about it.

Disclaimer: Follow these instructions at your own peril. I am not responsible for your errors or any incidental harm.

OK, with that out of the way....

First, you need some 100% DeoxIT. This is where I got mine:

Put a few drops (that's three) onto the 2.5mm plug on your headset. With a tissue, wipe the plug til it's coated with the thinnest film you can imagine. DeoxIT is so good, this is perfect.

Next, insert plug into Treo and spin the plug in the socket back and forth a few times. The thin film of DeoxIT on your plug has now cleaned the socket contacts. Really. You need so very little of this stuff, it's amazing.

Note: Do not drip, squirt, spray or otherwise insert anything into the socket on your Treo. You're almost guaranteed to break something.

As I was doing this, I noted, hey man, there's still some static! If you look at the plug, you can see the insulation interferes with the bottom of the Treo case, forcing the plug out of the socket ever-so-slightly, causing some crackling that you won't get rid of by cleaning. I recommend you either reorient the plug in the socket, or file the insulation on the plug a little until it doesn't interfere.

Hope this helps.