Have you ever wanted to create a nice little Web 2.0 mashup, but just didn't know where to turn to for an API that could grab the information you are looking to incorporate?

API's, application programming interface, are the source code that computer program libraries provide in order to support service requests. API's are often part of a standard software development kit, commonly referred to as an SDK. Companies that offer APIs range widely from Sony for their Playstation, Microsoft for Windows software, and more recently popularized in the online environment with Google Maps and many other online based mashups. As more and more organizations open up API's for developers to tool around with, that includes many that you visit online every single day, it gets harder and harder to keep track of what's available, and what is possible with them.

ProgrammableWeb has done a great job of supplying a comprehensive listing of all Web 2.0 API's. Anything from Google Adwords, del.icio.us, 30 boxes, Feedgator, BBC, Twitter and Zoho are listed here. All categorized and waiting for you to click and download.

Check out some API mashups we have profiled.