i did a quick test, and yes its a 3 minute MAX job, i found the pixel quality poor and the logo in the bottom right corner annoying.
like i said i spent 3 minutes on it so i can see it being very helpful for people who don't know how to do it via photoshop etc.
photoshop: don't ask me , ask youtube there are heaps of tutorial.
also photoshop CS2 apparently is now FREE, google it
tim