Hello I have actually successfully created a Ubuntu USB using unetbootin, however it is not persistent and will not boot on a mac. If anyone has any suggestions for a different application for creating this drive please let me know (it must run on a Mac). Or, if anyone has any suggestions on how to edit the .iso file so it boots from a Mac and is persistent, that would be great too. I am running OSX Mavericks so the application would have to run on Mavericks too. Thanks in advance!