While Tom is definitely bulgeriffic, and the swimming scene is obviously real, and there are plenty of other shots of him, where he's packin', if you look at the "floppy", frame by frame in the running scene, if goes from no bulge, to full flop, in about a frame. The "flop" also has the same "halo" of Smallville's other special effects (look at the bullets, for example). If you look at the frames that agentblue provided, there is "light source" all around the VPL, that is, there's NO shadow. Also, he's wearing jeans, and denim isn't typically that supple to show a soft flop like that. I think if it's not f/x, it's weird lighting on fabric folds, and not the flop that we all want to see.