I use my EVO with a wired headset. I work in a noisy environment so BT is not a solution. I have a Plantronics MHA100 (seen below) with a 2.5mm socket and jack. The MHA100 is a voice activated amplifier for mobile phones. problem is it hasn't been upgraded since it first hot the market some 10 years ago. Worked perfect even with my Palm Pre and the Black Berry 2.5mm to 3.5mm plug converter till I got the EVO. Problem is this. Since it is Voice activated when it hears sound on the line from either party it amplifies for 10 secs till no noise is heard. Usually works fine. On the Pre I could hear myself talk a little through the headphones, thus the unit would stay on during the time I was talking. Now with the EVO, I can not hear myself through the headphones and it shuts off till the other party starts talking. Irritating because it talks a second to turn on and I usually don't hear the first 1-2 words the other party says before it comes on. I also have 2 different converters. One of them works as described above, the other when plugged into the EVO makes the MP3 start playing as soon as its plugged in. IDK why this is... So the question. I have been reading up on the different styles of plugs and sockets out there being used. TT, TRS, TRRS ect. I would like to know what style the MHA100 has and what style the EVO has and how it works so I might be able to get the proper converter to 3.5mm and make it work on the EVO. Any electrical masters out there that can lend me a hand??