A new iPhone app, just launched at the DEMO 2009 Conference on emerging technologies, is aiming to change the simple act of making a phone call.

CallSpark – available soon for free download – has two main features. The first is a search engine for phone numbers that scours sources such as the white pages, yellow pages and yelp.com, and ranks results based on your location.

Useful as that may be, CallSpark’s second function could be even more powerful in terms of making and maintaining business connections: when making a call, CallSpark brings up data from social media sources such as Facebook and Twitter, along with professional networks like LinkedIn and salesforce.com, to give you a detailed picture of your contact’s history, location and mood.

mashable.com interviewed one of the developers behind CallSpark to get a better idea of how the new application works: