I setup Google Reader and found the funniest post from a kid that had texted Haiti 90999 on her cell over 200 times not knowing that she was actually making a $10 donation each time and had donated $2000 from her unknowing parents. That was one of the rss feeds. While it is funny it could be a major time waster, which is why I tend to avoid rss feeds. I just checked it again and there is a UTube Video of a cat dropping a monitor on his/her owner - again extremely amusing but not of much value!
I love Google Maps but wonder about the fears of loss of privacy when you can see everything at street level. I checked my home address and it must have been garbage day when they took the picture because the garbage cans are in my driveway and the recycling is on the sidewalk - kinda spooky really. Google Finance is great too except that lately I feel I want to be ignorant of what the market is doing.
If I taught Geography Gooogle Maps would be amazing. If I taught Business Google Finance would be great and I can think of how you could use it in Math with graphing, predicting trends and calculating returns. I like the Google Search that allows you to search for powerpoints on subjects and will use that. Google Books is the most useful for me in my area to find new ways to present the units that we do.