Boys can definitely be pee pad trained. I've had 4 males so far, and all used wee wee pads. I've found the "vertical target" approach works best.(As LadyMom mentioned). We use a 2 liter bottle filled with sand in the middle of the pad, and it works like a charm.
We even bought the little red hydrant for use outdoors. This way they pee where we want them to, and not all over the place.
By the way, both my boys are neutered but always lifted their legs. But NEVER marked in the house.
