Oh I just carry a regular ol' 16GB Sandisk Cruzer. I keep forgetting to order one when I order parts, but I am going with one with a read/write switch on it. I keep all my repair tools on it and antivirus programs like to delete them because they have "suspicious behavior". I normally disable the user's av when I plug it in, but that gets to be a pain. There's a lot of password recovery tools, debug tools, etc that the AV programs just assume are trojans or viruses (virii??). For a while though, I did run with a USB enclosure that you plugged a SD Card into, but it wasn't as fast as a regular thumb drive.