This the Ubuntu 11.04 desktop ISO for i386, written out to a 1Gb USB drive with the Startup Disk Creator, and then flashed back to a file with dd.
There are no customizations in place, no freaky wallpaper or third-party repositories.
Write this to a USB drive by inserting the USB stick, then checking the drive assignment with fdisk -l. Once you know the drive label, you can type
dd if=ubuntu-11.04-desktop-i386.img of=/dev/sdX
Make sure you change the X to the letter for your USB drive. And remember that anything you have on that drive is going to be overwritten.