...and I'm pretty impressed, I've got to say.
It's a Dremel Multitool 300 with an extra flex-cable thingy and a 55 tool pack (36 of which are identical cutting discs). £50 from B&Q.
I was expecting the cutting discs to kind of score the surface a bit before disappearing in a puff of smelly smoke, but they actually cut quite well through the 1mm steel chassis of the Sunblade 1500 case I'm modding. Have had to lay off for a bit, as it's getting late and I don't want to p155 the neighbours off.