Creating transparent PNG images

I'm writing an application from which it would be very useful to be able to output PNGs with alpha channel transparency so I can have semitransparent areas. I know it is possible to output PNGs but I haven't seen anything about full alpha channel support.

Is it possible to do this in GDI+ ?

You'll want to use this bitmap constructor overload:

Public Sub New(ByVal width As Integer, ByVal height As Integer, ByVal format As System.Drawing.Imaging.PixelFormat)

And this constant for the PixelFormat: Format32bppArgb