Web 2.0 refers to a shift towards user-generated content on the internet through social networking, blogging and other interactive platforms. It allows for easier information sharing and connectivity between people. Zoho Books is a Web 2.0 accounting application that allows users to invoice customers, track expenses globally, and collaborate with partners in real-time. Crocodoc enables educational uses like reviewing documents, getting feedback, and annotating reports. Google Timeline organizes search results chronologically within specified date ranges across various data sources.