How to make a USB flash drive bootable like a CD made from an ISO

I've had succes with both Windows and Linux iso's using UNetBootin. There are also several tutorials out there on how to use it with a Windows ISO.

HP has a couple tools that can be used to make USBs bootable. I've had mixed success with them depending on what it is I'm putting on them. Their strength, apparently, is that they are supposed to work with anything.

The HP Drive Key Boot Utility is one: http://h20000.www2.hp.com/bizsupport/TechSupport/SoftwareDescription.jsp?swItem=MTX-UNITY-I23839

The HP USB Disk Storage Format Tool is another. It works best for creating MS-DOS style boot disks: http://files.extremeoverclocking.com/file.php?f=197

I use liveusb-creator. It was designed for Fedora, but it's worked with every other live ISO I've put on it.