How to create a LVM testbed

Every once in a while I want to review/relearn a certain lvm feature. In order to do no harm, I want to create a testbed for lvm. Since I have done this a few times bevor, I now put all the commands in a little script, so that I don't have to type them again. Please note that this script does not do much checking, so please understand what it does bevor you use it, and use at your own risk :)