I have been using this tutorial for creating bootable USBs:
http://www.teamteabag.com/2008/05/17...tros-from-usb/
I installed KUbuntu 8.10 and 8.10 DVDs by following the 3-4 steps mentioned in this link. Except for the extraction part it is very easy. Extracting the files from the iso image to USB takes around 1 hour in my case.