Arch Linux live USB image
Arch Linux is a really nice distribution that will send you down the learn about Linux again path. Even reading the installation manual, I end up spending two hours reading up on what the best bootloader is and whether I want a DOS or a GPT partition table. This post is just to give you a quick image to download and instructions on how to resize it, you should follow the live USB wiki page for the full experience.
After getting bored of reading, I decided to go for an old DOS partition and syslinux with a 64 bit kernel. Following the wiki page, I created an 1.2GB raw full disk image with an Arch Linux live USB installation on it. After uncompressing the XZ file, the raw file is perfect to dd onto any USB disk:
dd if=archlinux_live_usb-2013.03.01.raw of=/dev/sdd
After doing that, simply boot (you can use KVM also) and resize the partition to fill the disk. One way to do this is to recreate it using fdisk /dev/sda. Remove the single root partition (d) and add it again (n) at full disk size:
fdisk /dev/sda
p
d
n
p
1
<i>hit return twice</i>
a
1
p
w
Do not forget to set the bootable flag (a). Then reboot and use resize2fs to resize the filesystem to fit the partition again:
resize2fs /dev/sda1
After this you should have a very bare Arch Linux installation on your USB drive.
You can now use pacman to install extra packages (base-devel) and upgrade the system.
Download it here and have fun!