I saw this design on a friends blog yesterday and HAD to try this myself!
I've used two coats of No7 French Pink followed by the dripping effect with a Stargazer nail art pen (from Just Beauty in Bath). These pens are great, just like the Models Own ones however at £2.99 they are half the price!
I finished off the look with my amazing fast drying Nails Inc topcoat. :)