Eva loves to be on all fours, even though she needs help to get up there. She is just starting to do the rocking that precedes crawling... I think we've got a bit of time before crazy babyproofing v.2.0 must occur.
And by writing that above statement out loud I have probably just ensured that she will learn how to crawl next week when I am in the bathroom and launch herself down the stairs. Good luck kid!