DeKnop

From Thuis:

DeKnop (dutch for "The Button") is a graphics editor that is designed to let you create buttons for your web site without requiring any graphic design experience. It provides an easy to use step-by-step interface that lets you select the text, font style, color, 3D bevel, size, gradients and many other aspects.

You can preview any changes that you make as it takes place, so it is easy to experiment a little until you decide on a design you like.It offers support for automatic up or down effects for use in mouse over java scripts as well as gradients and more.