Google provides developers with many tools and almost of them have their APIs for easier integration with 3rd party services. Finding out the full list of all products and API’s can be difficult task. For this Google now has a new web page: Google APIs and Developer Products.
The page has a full periodic table built out showcasing all Google APIs and developer products as of January 2011.
At the top of the page you can find the categories under which the APIs or products fall. Categories included are: Mobile, Search, Gadgets, Data APIs, Social, Misc, Ads, Geo, Tools, and Chrome. If you hover over a category it will highlight the corresponding “elements” on the table, and clicking on an element will then take you to that API’s home page.