I tried this keyboard with my Treo 650. It was very difficult to get it to work. I used the web download to automatically download the most current drivers (or so I thought) to my Treo. That driver didn't work. I then used the driver that came on the CD. Finally worked, but only if I unchecked "reconnect," which is the opposite of what the instructions said to do.Once I finally got it working, I was very disappointed with the accuracy of the keyboard. I could barely type anything without some kind of typo caused by the keyboard. The space bar in particular repeatedly failed to register, and I very frequently had to go back and insert a space.Overall, I found it not much faster (and tons more frustrating) than just using the tiny thumb keyboard on the Treo itself.For the $$$, I would expect a lot more.I do not recommend this for people used to touch typing.