We have confirmed the Rokland n3 wireless USB adapter is plug and play with Ubuntu 9.04 Desktop Edition (Jaunty Jackalope). We have run tests on multiple computers to be sure. On one system we ran the Live CD version of Jaunty, and on another we installed it to the hard drive. On both systems the adapter did not require driver installation and was immediately able to connect to access points using the wireless connection utility located on the top menu bar of the desktop. The process was very simple- just boot up the system, connect the n3 to the USB port, click on the wireless connection utility and select your network.
If you are not able to get your Rokland n3 working on Ubuntu 9.04 Jaunty, open a terminal window and run iwconfig to see if the device is listed there. If it is not, confirm that your USB ports are recognized by Jaunty. If no other USB device (such as a mouse or keyboard) works with your computer, that means the problem is your USB bus is not working right in Ubuntu. If your USB ports work fine, please report the issue to our support department.