Things 18, 19, 20, 21

Google maps are good for getting directions and also just for playing around such as looking at your house or other people's using street view.
Google docs is very useful if you don't have Microsoft Office or other word processor. There are other free word processors such as Open office that have been around for awhile so if people didn't want to pay for a word processor they may have already used a free one so Google docs may not be a big threat to Microsoft Word.
Google book search is good and I have used it quite a lot even before doing 23 things.
iGoogle home page is good, because I can check Gmail without having to log on again and it is good to have all the extra information on hand. I added the artists theme so that I have a Leunig picture as a banner and it changes from a day time picture to a night time picture depending on the time that I am using the computer.