These are all organizational tools--online calendars, task lists, personalized starting points from Google, etc., and as such they would primarily be useful in libraries as an aid to library administrators to assist them in keeping their act together. Other than this rather abstracted notion of helping our users (through our own increased efficiency) I'm not sure what the direct application would be. But then, I'm tired. Who knows--maybe I'm missing something obvious. Ummm, helping users track when their books are due? Seems like we've got that pretty well covered. I get automatic email reminders when items are coming due, which is a great service.
Starting off with iGoogle: I fell in love with this instantly. It is, however, the opposite of a productivity tool. When you set up iGoogle as your Google search page, you get all sorts of personalized tabs. I have Home, Minneapolis, News, Cooking, Politics, Business and Art. Each is its own page. You can customize what portlets you view on each page. For example, I removed Fox News from my news page. Then I moved the remaining portals around so CNN and NY Times were organized front and center. I believe I mentioned recently that I'm elitist, so this action will come as no surprise. For the Cooking page I added the "World's Healthiest Foods" portlet (for today: swiss chard). A surprisingly fun thing to do is change the "theme" of the header for each of your pages. There are lists and lists of themes, each by a different artist. You can also add a zillion gadgets wherever you like. I added a portal that displays the current phase of the moon. (Waxing Gibbous, one of the lesser known American Transcendentalists.) I say it's the opposite of a productivity tool, though, because it's very easy to get sucked into any one of the portals. And God forbid you add the Tetris gadget. (Does anyone else remember Tetris? I know people who flunked out of college because of Tetris. Well, at least partially because of Tetris.) So, for the self-disciplined a big thumbs up. For those like me, iGoogle should probably be avoided in the workplace.
Online calendars: very nice, but I use my Outlook calendar efficiently enough, thank you. This also reminds me of a blurb I saw years back for an amazing information technology--it was lightweight, easily portable, had a finding tool built in, easy to navigate, easy to mark. It was a book. A printed book. So let's not get carried away here. I also use a real, honest-to-goodness calendar to track my activities.
Ditto with the list managers. I tried out the one called Remember the Milk. This is useful, but isn't a piece of paper also very useful? And lighter? And doesn't require a power source? Am I missing something?
Summary: I'm an iGoogle convert. I'll wait on the rest until the capability to just plug into the hive mind is fully functional.