4 shots in One - Can it be done in PS?

[mmcclusk2]

Ok, I just got my new Canon D10 D-SLR and I love to take Mountain Bike action photos. It can take 3 fps, I can get cool jumps and stunts in series, like this example photo.
http://www.mattmccluskey.com/misc/sequence.jpg

The question is: How do I take the indiviual photos and put them on top of each other to make it look like the photo above? I'm sure it has to do with layering and opaque-ness. Is there an easy way to do this or is it going to be "majic wanding" the rider? (Which I suck at doing :( )

[Conk]

It's actually very easy. You can add every photo as a layer. After adding a layer just erase the area to expose the image underneath. Do this with each layer. All you are doing is basically punching holes in each layer.
One thing that is critical in doing things this way is that the photos are all shot on a tripod.