DS is a major wriggler. I usually give him a toy while I clean and have learnt to put his nappy on with him upsidedown (on his tummy), he stays stiller on his tummy!
Yeah, I've had to put his nappy on whilst he's been on his tummy, I did find it tricky working backwards though, I've also had to put one on whilst he's standing, determined little so and so! I love him to bits though.