I'm a bit late on the bandwagon with this one. I bought it weeks ago, but every time I tried it, I didn't like the effect, and it wasn't strong enough, or I couldn't photograph it well enough. Last night I tried again, and I got my good camera out to take the pictures, it worked much better! I did have to use the flash to get the effect to show well though, the natural light here at the moment is crap, the weather is like we're in Forks.
My magnetized polish is from Boots No17 and is in the shade 'Lilac'. I'm sure you all know how the whole process works, so I won't go into that. When you do the magnetizing though, it does feel odd how you can feel the pull!
I think I paid about £4 for the polish when it first came out, but it is more normally. It is so easy to do and I love the effect. I most definitely want to get the other shades.