I also like this pattern and asked Tripletmom how how made them.........here is her answer:
I have done the feet 2 different ways.
The one on the cake was made using a template that I drew on paper for the foot part. I cut around the template and flipped it to get the other foot. For the toes I rolled a 'snake' of fondant and cut off pieces in 5 different sizes (2 of each though) from big to small, for each pair of feet. I then rolled these into little oval balls and flattened them gently and these became the toes.
Another way is to get a metal cookie cutter in the shape of a little foot and cut the feet out. I say metal because you can flip the cutter to cut the fondant to get the opposite foot...or you could just turn over the fondant itself, it doesn't really matter. I made the toes the same way was above and applied them directly to the foot print.
You can also do a search on google for 'baby feet' and download a template that way as well.
thanks dogluvr & Tipletmom
Party city has the baby footprint cutters in the baby decoration section