[How to replace one color with transparent]

This has been bugging me for a while.. How do you replace one color in an image, say white, with transparent? I tried Recolor but it doesnt seem to be working with alpha.

[The Pictorium! Post your created or edited images here!]

[layer masks and custom brushes]

Heya,

I've been using Paint.NET for a while now and I think it's an awesome program. Learning Photoshop lately however I think there's 2 areas that would really help Paint.NET, that's layer masks and custom brushes.

In the brush tools I know you can select from a drop down of preset brushes, but is there a way to create custom ones? That's one feature that can be really useful for creating textures and such.

The layer system could also use a lot of improvements, but layer masks especially. Any plan on adding these things in the near future?