1. Start off with a work area big enough for your button. Create a new layer and then select the Rounded Rectangle Tool and make the radius 5px. Draw your button out but try not to make it too high or it's not going to look right when we're finished. It should look something like this.

2. Now double-click on that new layer to open the Layer Style window and match my settings below.

3. Now for the tricky part. Select your gradient overlay in the layers window and try to match my settings. You'll have to slide those bars around until it's just right and it make take you a couple minutes to find the right spots but once you know where it's at you'll never forget it.

You can change the colors around to create any color button you want. Below is my original "Aero" style button and a black "Vista" style one. All I've done is changed the colors we used in the layer options (above). My text is a simple font with a 1px stroke to make it stand out. I think the colored buttons look a lot better than the black ones with this effect.

If you want a cool mouseover effect, increase the brightness of the image and ta da...