Since I've 2 netbooks - Acer Aspire One AOA110 and Lenovo IdeaPad S10, I wanted to buy a USB bus powered portable DVD drive without the need for an external power adapter. I tested three such drives - LG GP08 ($133), Panasonic UJ-880A ($125) and Buffalo DVM-P8U2/BW-AP ($80).
LG GP08 was not detected in the BIOS of both AOA110 and S10 so I can't boot from CD/DVD to install any OS but can be used within Windows. Both Panasonic UJ-880A and Buffalo DVM-P8U2 were detected in the BIOS of the netbooks.
In the end, I chose Buffalo DVM-P8U2 because it is cheaper and the pearl white colour matches my S10. The only downside is that it can't read/write DVD-RAM which I don't need.