As always, it's so good to find out that I'm not the only one!
My LO is 11 months old, and has gotten increasingly wigglier as she gets older. She's recently learned how to push herself over into a sitting position from hands and knees, which has greatly complicated our nursing to sleep routine. Like others mentioned, she sticks her little bottom up in the air and wiggles it around, then pops herself off, and now she's added the sitting up part. This has made going to sleep at naps difficult (as in, not happening), so we've just re-instituted the rocking chair for nursing to sleep for naps. Fortunately at night we have a long-standing routine of nurse-wiggle-nurse to sleep.
Babies are SO funny!! Thanks for all the hilarious stories!