found here) and I am definitely a fan.
Along with the Dremel, I purchased some rare earth magnets from K & J Magnetics that are the size the video suggested. Today I will be magnetizing almost all of my Carnifexes as this is a project I've been wanting to do since I started Tyranids back in early 2009. Also, today I should be getting in some Balrog wings that I ordered from Games Workshop so those will also get magnetized for my Hive Tyrants (which also will be magnetized as all of the Monstrous Creatures can have several different weapon variants).
So, long story not short enough, if you are on the fence about whether to purchase a tool like this I must say it is totally worth it. It has already let me accomplish in minutes what would have taken all night otherwise.