This works great with my Mp3 phone:
NNTN5774 Nextel Sprint OEM Stereo PTT Headset $15 bucks on ebay

umm

u need stereo headphones

not a monophone heaset

try motorolas ht 820

fits well and is wireless

Can you tell me exactly which headphones you have? Do you need any adapters to make them work properly? I've bought 4 pairs (3 of which were through cell phone stores that insisted each model was compatible with my Treo). But I only get sound through right ear. After 3 hours on phone with Verizon support, they sent me a new phone. Guess what, still sound in one ear only. I've seen some postings that certain headphones are not compatible, only problem is noone says which ones are proven compatible. I'm tired of returning headphones!

Thanks.

are you trying to listen to music through a bluetooth headset? because that will not work unfortunately. i purchased a pair of stereo headphones with built in mic so i can answer calls as well as listen to music, works great. you can find some good deals at either mytreo.net | The largest Treo resource | Downloads, forum, accessories, reviews and FAQs or http://treonauts.com

Good Afternoon Everyone...ok..Thanks to Mustang Lover I've turned the Treo into a Mp3 playing machine....as far as headsets Ive found the post of recommendations;however, when I tried a Motorola headset...it just didnt work....is there an adjustment to be made on the Treo?