Gary,

A full set of instructions for using UNetbootin is on the wiki page below the download link. http://sourceforge.net/p/chirplivecd/wiki/Home/

Short answer:  Xubuntu 12.04_Live

also, make sure you put a number larger than zero in the "Space used to preserve files across reboots (Ubuntu only)" box.  Again, see the wiki.

Bob

------------------------------------- I down loaded UNetbootin and installed on a micro SD card in an USB adapter. When I ran the program it asks me to Select Distribution and than gives me a list. Which one should I choose? My operating system is XP.

GaryErrol