Camophone.com
Who do you want to prank call today? I have never had a need for this type of service, but it sure looks like it has entertainment potential. It's even cheaper than most long distance services. It's still not as cheap as Big Zoo. It just looks so fun!

Google Desktop Search
Oh, yeah!!! Forget about Windows' Indexing Service. Now you can get relevant search results of your own hard drive's contents. Those wizards at Google Labs deserve a raise!

NOAA: WMO Resolution 40
Want to know what the weather was like two years ago today? In another country? Here you will find daily summaries of weather data from nearly 8000 stations around the world. Some of them have up to ten years of data available. It's all in fixed-width ASCII format, so you can import it into your favorite spreadsheet program, etc.

I downloaded the whole thing. When it's decompressed, it takes about 3.5GB of drive space. If you don't want that much, you can select just the time periods that you want.

I should also mention that it does not include measurements of relative humidity. If you want that, you can calculate it from the temperature and dewpoint. The formula is at http://www.srh.noaa.gov/elp/wxcalc/formulas/vaporPressure.html.