As the mother of two changing table wrestling champs I can sympathize. Here's what's helped (though not always worked) us.
1) As pp's mentioned, a special book/toy for the changing table only. I, sometimes, keep a small container of crackers or pretzels on the table to give out during changes.
2) Get to the store and buy a flat, crib mattress protector. Better yet, buy two. NOT the fitted kind, just the kind you lay flat on top of the crib. Lay it on the floor in front of/next to your changing table and change your ds on that. It will help you tremendously to get him on the floor. These pads are fairly large so even if he rolls and pees he should still be on the pad.
3) Sing. It sounds nutty but sometimes it worked. Kids can be very distracted by a favorite song. Even better if you can come up with a special diaper song.
4)He may need a model of what you want. Put a diaper on one of his stuffed animals first. Make sure he is watching. Praise the stuffed animal for staying so still for Mommy and thank him/her for being so helpful. Then tell ds it's his turn to help change his diaper. Be sure to thank him when he does cooperate. When he doesn't, tell him you are sure next time will be better.
5) I don't know if you cd or if this would work for sposies but sometimes it helps if I have dd pick out the diaper she wants to wear. Even at 16 months old she already likes to pick out clothes, so if she's picked the diaper she's more likely to hold still.
I hope you find a solution, at least a part-time one. I'm sure you're both dreading changes at this point.
