According to Chris Shipley, "CallSpark is doing for phone calls what Google did for Web sites, by enabling people to quickly fin accurate information in the context of a phone call".  CallSpark's plan is to enrich the calling experience.  Not only do they provide you with any phone number you may be looking for through their cloud that crawls, the white-pages, yellowpages, salesforce.com, and even multiple gmail accounts but they also make custom "RingPages" which are optimized for mobile use.

From the Press Release:

Pre-Call

• CallSpark’s “Social Dialing” and “Keyword Dialing” deliver faster, smarter calls. Search and dial from multiple data sources including private (e.g., Outlook, Gmail, Salesforce.com), social networks (e.g., Facebook, Twitter, LinkedIn), and public (e.g., Yelp, White Pages)—connecting your address book to information in the cloud.
• Proprietary CallRank™ algorithm uses location-based search and individual and group call history, enabling you to find what you’re looking for in a fraction of the time.
• Whether viewing a friend’s Tweet or a local restaurant menu, CallSpark allows you to be fully informed about the person or business you are calling before you make a call.

During-the-Call

• Receive real-time data from the cloud about friends and businesses you are calling, including full Salesforce.com contact and lead information for business contacts and social networking data for friends directly on your smartphone screen.
• RingPages™ for individuals can be customized so you can control what other people see when they call you with social networking updates from sites like Facebook, Twitter, and LinkedIn displayed directly on the smartphone screen.
• Customized RingPages™ for businesses goes beyond simple listings, providing immediate mash ups for mobile, including location, time, etc.

Post-Call

Log your sales calls into your Salesforce.com account.

Checkout our interview with Wendell from CallSpark as he tells us more about CallSpark and gives us a walk-through: