I think the nice thing about the data they hold is that very little of it has any real switching costs. I use gmail a lot, but I forward it all to my Exchange Server. I use Analytics, but could switch to another provider without too much headache. Same with YouTube and search.

I can't think of anything they even own that has a strong switching cost, other than maybe BlogSpot (it's really hard to change a blog's url and move readers over there after losing organic search) and FeedBurner.

Google has set itself up as the go-to for not only as the fount of knowledge but also, more recently, where we store and create the content that we are sharing with others. Besides “native” services like Mail, Cal, Docs, Sites, Notebook, Chat, Analytics and Groups which set Google up as the storehouse and gatekeeper for our personal data, acquisitions like YouTube and BlogBeat have a lot of value in both generating more accurate searches (taxonomy through tags and tracking of what's good by rankings) as well.

While I love the company enough to own stock in it, it also scares me that one day they'll decide not to follow their motto. It's scary to put so many of my eggs in one basket but they make it so darn easy and convenient that it's hard not to.