Google Docs and Spreadsheets--Easy-to-use and useful especially if you want to work on the same documents from different computers (work and home, say), so long as you can access the internet from each. A company called Upstartle created the word-processing program formerly called Writely, a name now associated with its warmer, more intuitive layout. Google acquired Upstartle in early 2006 and recently integrated the program, coolly minimalistic layout scheme and all, into its increasingly vast suite of products.
How does a company that built its brand on simplicity of interface manage a growing and disparate constellation of brands? To segment or integrate? Pragmatisim and the acquisition of YouTube, as it stands untouched, suggest the former, but integration is the Google holy grail--quick access to all the world's information--so I think we can expect a hubristic pursuit of the latter.
The civil libertarian in me prefers segmentation, but the information hungry techno-utopian in me prefers integration (hook it up to my veins!). But as Mike points out, Google could reconcile these opposing impulses, or at least mitigate their exccesses, if: they "create a digital privacy tool for all its users that would let them view, delete and set expiration dates for all data that's collected about them." I love it. Such a digital privacy tool would allow the civil libertarians to scale back without abandoning Google for the mailman and library catalog, and the techno-utopians, meanwhile, could go hog wild and force feed Google personal information to help optimize their web experience.
Be sure to read Mike's whole post.
Addendum: Examples of Google integration abound; for instance, I just came across this one: Okrut & Google Talk.