I have just listed my Touchstone 2 with Audio Out for sale on ebay here:
HP Palm Touchstone 2 with Audio Out Phone not Included Extremely RARE | eBay
This is the same unit that appeared on this site:
PreCentral forum member goes hands-on with swanky Touchstone Audio Dock | webOS Nation
Since I am no longer using my Pre3, I decided I would put it up for sale for someone who can still use it. I could never go back to a standard Touchstone after using this thing. I never really used it for audio - but the profile while holding the Pre3 is SOOOO much better than the original TS.