Great price for a 4gb M2 micro, but not as described - last two words of quote below are all-important!
"..exchange data with standard-size Memory Stick PRO compatible products by inserting the M2 into the supplied adapter"
wanted to use this in my PSP and was upset to find the 4Gb didn't come with an adapter but the 2Gb did. Reported this to play and now awaiting a replacement (fingers x'd it has the adapter).
I have a Sony Ericsson K800i. Works perfectly, never had any issues with it. And am about to buy my 2nd card for another phone.
I just put it into my phone and have an amazing amount of MP3's and photos on my card.
A must buy for anyone looking for a lot of extra space.