Unfortunately for both of the negative reviewers of this item here on Amazon, you must be sure that your devices (phone, pda or whatever) supports the a2dp BT profile, if not YOU are making a stupid purchase.(I have yet to see any solid evidence that the w600i supports the a2dp bluetooth profile, and even if it did the carrier probably disabled it in the phone ROM; carriers often delete features from the phones they sell so they don't have to bother providing tech-support on those more complex often unused features, along with other reasons...)Yes, it is unfortunate that the Bluetooth standard did not end up being as easy to use and ubiquitously interoperable as the manufacturers first hyped it to be, but that doesn't excuse you from failing to do the proper research to ensure that you were/are making an intelligent purchase.If your phone does not support a2dp or avrcp you shouldn't buy these headphones for your phone! I have heard from several sources that the headphones are fully functional with the WIDCOMM bluetooth stack, so if that's the type of BT adapter you use on your computer you should be all set (I don't know for sure if the standard Windows BT stack will fully support them or not, I have the WIDCOMM so I don't care...). And of course they should work fine with any Motorola BT adapter (mini-jack or USB).I personally just finished my pre-purchase research on bluetooth headphones, and I will be purchasing this set. I have a T-Mobile MDA (PDA/Phone), and even a device as advanced as this does not natively support a2dp, but thankfully I found a registry/app hack that fixes this. (remember what I said about carriers deleting advanced features from phones?)I just find it sad that people buy BT peripherals that simply won't work with their devices and then write really angry reviews about how the devices don't work; well DUH, do the research to make sure it CAN work first dummy!Calling the free tech-support provided by your carrier can save you a massive headache from trying to get incompatible devices to work together; as well as the headache of trying to return a mail-order purchase.If you are not 100% sure that your device (phone/pda/mp3 player or computer Bluetooth adapter) will support a2dp or avrcp CALL TECH-SUPPORT AND ASK! Or do the research online so you are sure, because if you end up buying an incompatible device 99% of the time it's YOUR fault for not double checking!I do agree however that the advertising for BT devices sucks, the manufacturers lead you to believe anything will work with anything else, and I am not defending the manufacturer's advertising practices. But since anyone CAN figure out the compatibility on their own I encourage them to do so!!!(I am lodging a rating based on my experience with a set of these headphones a friend of mine has, I have spent numerous hours testing/fiddling with it and successfully paired it to my hacked T-Mobile MDA using the a2dp BT profile, and it works PERFECTLY, great audio quality and flawless phone answering!)