The Isostick, a Kickstarter project now in development, is meant to emulate an optical drive in the form of a USB stick.  Although there is nothing new with putting an iso file (optical disk image) on a USB stick, what is unique about this drive is that it fully emulates a drive without actually having to worry about drivers or extra programs.

When plugged in, a computer sees a flash drive and a virtual optical drive.  An excellent feature is that this disk can store multiple “iso” files and select them with a built in utility program. This could be invaluable for a technician or hacker since more than one CD or DVD is often needed to complete a task.

If fully developed, one could expect to attach this “drive” to your keychain and not have to worry about lugging an optical disk around anymore. Also, the activity light is programmable, which is a nice bonus.