The 600 million numbers that Truecaller has in its directory have been collected via crowd-sourcing. Truecaller’s users can share their contacts and in return they get access to search in the collaborative database. Thanks to this collaborative data solution, the directory is growing and being updated continuously. It also contains numbers that no other directories have, e.g. pre-paid phones.
Chart APIs are useful and popular, and Google knows how to do them well, so they're continuously adding more features and options for customization to their Visualization API. The Google Code Blog recently highlighted a few of the newest features.
Scrapplet, a service that's a cross between a Netvibes-style start page builder and a browser-based mashup environment, this week released a set of new features for integrating web-based content within the browser. The basic service allows users to build their own web pages by dragging-and-dropping content like text, video, widgets, feeds, etc from other web sites.