I like Google. I use a variety of their services, and I find most of their products and apps very useful. Here are some of my favorite Google Tools:
Google Hotel Finder
Find hotels by various criteria, such as location and price.
Search and compare prices of flights.
Google Lit Trips
Create geographic presentations of literature. Very cool for book clubs and class discussions.
Google Product Search
Find the best product for your needs. For example, if you type "ebook reader" you get a list of devices, who is selling them, and at what price. You can limit results to a price range, to only products that are currently in stock, only those with free shipping, with or without wifi capability, by brand, and by several other specifications (screen size, multimedia capability, etc.)
Find a picture of just about anything! You can also limit results to creative commons images if you plan to re-use them on your own creation.
Find videos in various sources. YouTube is great, but you only get YouTube videos when you go straight to that source. In Google videos, you get results for sites like eHow.com, cnet.com, discovery.com, and YouTube (and about a million more!)
Google Maps and Google Earth - I like the ability to "search nearby." If you find a hotel, you can "search nearby" for restaurants, malls, or whatever.
Google News - up to the minute...literally
Gmail - I'm a huge fan of the labels vs. folders organization and the ability to see an entire conversation in one file.
Gchat - You can choose to have chat transcripts saved in your Gmail account.
Google Documents - Ability to share documents with a web link and collaborate on them with others.
Google Calendar - You can share these with other Google calendar users, too. You can also color code your life, which is fantastic!
Google Reader - I'll admit, this one is falling a bit farther down my list of Google loves. The last "upgrade" was a downgrade. One of the things I loved best was the ability to click the "share" link at the bottom of a blog post and have it list automatically in the "Shared Items" box on my own blog.
Related tools that are owned/hosted/whatever by Google:
Picasa - online photo storage and sharing
Blogger - HollyHibner.com is a Blogger site.
Android - operating system for my phone, which I love
Picnik - online photo editing