Mandriva Seed is a lightweight application that will help you easily put Mandriva 2010 on a USB flash drive. The portable device's storage capacity depends on the size of the Mandriva ISO image you use.
To create the Live USB, all you need to do is download the seed tool, select the ISO as well as the target device then click the button at the bottom of the main window.
As soon as the tool has finished, you should set the boot menu to use the USB device first and you'll be running Mandriva from your flash drive in no time.