I followed this guys tut which basically encrypts a piece of your drive. I am trying this on a external and it keeps giving me a error when creating it. http://www.youtube.com/watch?v=1Kd3eXm_DDA&list=WL23CA8A66C58A5123 Here is that same tut in text form - basically just creates a image on the disk. http://support.apple.com/kb/HT1578 Can I use true crypt on a external drive? Or the method linked above? I see using disk utility i can encrypt the drive. Can i do that without erasing the entire thing? I just filled it up i don't want to erase it all to partition it again.