GooglePages by Jan Albartus
Google has a neat video site where you can share your video's. Quite a nice feature is that they allow you to embed their video's in your own webpages or blogs.
This application is unique by offering a complete 3D earth to navigate. A great thing is the ability to create your own content with Google's SketchUp or applications like Blender.
This website was created using the Google Pages' online editing tool. It offers a free 100MB website. The website's design is one of the templates provided by Google.
Google Gadgets are small webapplications that consist of an XML that 'wraps' normal web content. One of the neat things is you can make your own Google Gadgets that people can use.
This gadget encodes / decodes USD (Up-Side-Down).
Google Groups offers users to set up a mailing list.