All you have to do is load your images into ImageReady which comes with Photoshop, and create the animation there. It's easy to do, and I imagine there are tutorials out there that will teach you how.
ImageReady is very powerfull, and works great for animation. It can even generate animations on the fly using the first and final frames of the animation; allowing you to choose how many frames you want.
You know, even though Photoshop is an expensive software, it seems every one and there brother supposedly went out and bought it. Which I find hard to beleive considering half of them don't know how to use it! Sorry (I'm not talking about you Adz) I'm just blowing off some steam.
I've got DBClassic and Photoshop Skillz and I'm not afraid to use um!