I just played with Marquis Who's Who on the Web, the online Who's Who database. (You can get a free 1-week trial membership. It's pretty cool. I could spend many happy hours
being nosy doing research in there. You can, for example, search by zip code and find out which famous people live near you.
I love my Ancestry.com subscription, which I use a couple of times a day as a phone book and such. Marquis is in the process of putting all the bios from their many publications into one big, searchable database, and they're also including the historical books. So this is much better than having copies of the books. I haven't jumped yet, but I'm thinking about getting a subscription.
It's not perfect. It took me three tries to find my own listing. First Name = Kathryn, Last Name = Cramer didn't do it. A search by zip code didn't do it either, but did pick up my husband's listing (plus a long list of people around here I might want to get to know). But searching on Cramer by itself did the trick, picking up both my dad's listing and my own.
Also, one can now pay them an annual fee to put your own listing on the web if you want it to be publicly available to the ordinary Internet user. This seems to be a very new service, since a Google search of the site where these are hosted turned up only a few dozen entries; when I inquired about pricing, there was some confusion about how much it costs. But in these days when anyone can become your biographer whether they know anything about you or not, it looked to me like a useful service.