Most of you will have seen this video before
http://www.youtube.com/watch?v=omlIXsk-Y4k
And that recently B&Q seem to have stopped selling the oyster tool. Having missed out on them I just got my hands on one from -
http://www.bes.co.uk/products/152.asp
Tool works great and with a little tweak to make a full ring then you can easily bead your own tubes