I am making a cake for a friend in the shape of his iPad. I just got a picture of his and his background is grey that fades into blue with water drops all over. I really don't want to use an edible image. I planned on air brushing the grey and blue but have no idea on water drops. Any ideas would be great. Thanks.

I would hand paint it.

How would you hand paint it to look like water?

I'm just learning how to paint cakes, but my initial thought would be to paint a droplet with a thinned out white colour, so that it's not a thick white, and then drag in the sides of the droplet and round them towards the bottom/middle (does that make sense?) to create contour.
I'll get a peice of Fondant out tonight and give it a try, so i can post a pic of what i'm talking about.

I would use clear piping gel..Sometimes when I am doing a Tinkerbell cake I use this to make the water droplets behind her...Works great!!

If you Have worked with gelatin you might be able to paint little water droplets then let them dry. Another option is the cake play isomalt sticks. You could make droplets on a mat and once they set up place them on the cake.

So i don't havesny lighter colours on hand for some reason right now so i cant try my technique at the moment..
However I did try a bit of pearl luster dust thinned with clear extract, and then i painted droplets right onto the fondant with a really small paint brush, and it turned out great! I liked how it shimmered just like a water droplet would.