1. Play videos from Google Search
Google lets you play videos from YouTube and Google Video directly from the search results pages. That means you can search for a song, an artist, a TV show and play videos just by clicking on "watch video". E.g.: Mika.
2. Better translations
This year, Google moved to its own statistical translation system, which provides better translations, improves faster and it's easier to scale to new languages. You can access the service if you click on "Language tools" at google.com, from translate.google.com or if you translate search results from foreign languages.
3. More recent web pages
Google indexes web pages faster so you can find them minutes after they're published. If you want to restrict your search to recent pages, there are more options in the advanced search that let you find pages first seen by Google in the past 24 hour, past week and other intervals.
4. Find geographical information
Google Maps is more than a search engine that finds local businesses, shows maps and directions. It's also useful to find content related to a certain place through mapplets or directly from the search box. Find photos, videos, books and maps from the web.
5. Free 411 in the US
GOOG-411 lets you find a local business and connect to it by calling to 1-800-GOOG-411. The service is free and doesn't have human operators.
6. Trends in search results
If you wonder what are the most interesting searches at the moment, try Google Hot Trends. The data is updated every hour and shows the queries that had the most spectacular evolution. For now, Google Hot Trends is only available for the US English version of Google.
7. Explore the sky
Google Earth 4.2 lets you switch to the sky mode and explore stars, constellations, galaxies, find information and high-resolution images.
8. Find faces in Google Image Search
You can restrict image results to faces by going to advanced search and selecting "faces" in the content types section. Google's face detection is really good and you can use this new option when searching for people.
9. Go mobile
Most Google's services have a mobile version and they should be available by going to google.com on your mobile phone (or google.com/m on your computer). There's a unified interface for iPhone, a great mobile version of Google Maps that finds your location even if you don't have GPS and a mobile YouTube.
10. Download StarOffice for free
Of course, you can always get OpenOffice, but Google lets you download for free a more business-oriented version that normally costs $70. The price is that you need to install Google Pack, collection of applications recommended by Google. You can still choose the software you want to install and it's easy to uninstall Google Pack while still keeping StarOffice.