This one makes me laugh. There is no shortage of content for baby crawling videos. I think this baby crawling contest is my favorite.

Interestingly enough, I just found out that since parents have been encouraged to put babies to sleep on their backs to prevent SIDS more babies crawl later or actually skip learning to crawl and go straight to standing and walking. Apparently the way to encourage a baby to learn to crawl is to place toys and so on just outside of reach. Cool stuff.