Peppermint Sticks :)
On the left is my Peppermint OS and on the right is my Peppermint Ice.
Both are equally powerful and very lightweight.
I use peppermint all the time to boot into pc's that cannot boot into Windows
to retrieve files and back them up on an external hard drive.
To put peppermint on a USB thumbdrive for you download the following:
Run Unetbootin to install to USB thumbdrive :)
Here are a few screenshots from both.