Ranked in these QuestionsQuestion Ranking
Pros
Pro Allows "persistance" for select ISO's
You can create a "persistance" file of up to 4GB (depending on USB stick space) for many current live CD ISO's, which means you can live boot, install a few things, save a few docs, then shutdown & move to another PC with the same files intact (tested by installing Minecraft :)).
Pro Multiplatform
Windows, Debian package, RPM & source available along with a number of unofficial builds (Arch, Slackware, ROSA, Gentoo).