Heres another boring tutorial by Akaiho....
1.Create a new image with the size of 70x70.
2.Create a new layer by clicking Ctrl + Shift + N
3.Make a rounded selection using the Elliptical Marquee tool. To make sure that it is exacly rounded, press Shift during the selection.
4.Fill it with any color and then you may deselect it.
5.Make this layer style for the circle:

Still in the layer style of the circle, add a color overlay with 100% opacity of the colour you want the button to have. I gave it an orange color of the tutorial.
6.Do this with the sphere layer selected:
Select - Load selection - Layer 1 transparency
7.Select the Rectangular marquee tool. With the Alt key pressed deselect the upper and lower part of the sphere letting a rectangle in the middle.

8.Now that you have a small rectangle selected in the middle of the sphere, create a new layer (Ctrl + Shift + N) and fill it with color.
9.Make this layer style to the rectangle:

Also, make a color overlay with 100% opacity with the same color you used for the sphere.
Now add your text to the button!
10.Delete the background layer.
11.Save the image as GIF, so that you can put this button on any background using transparency.
Final result:
THE ENDTutorial by: Akaiho