Jajah. http://www.jajah.com/ …. Server-centered VoIP plus PSTN for consumers. You make a phone request from your PC or mobile phone, providing the two endpoint numbers. Jajah makes the call over VoIP and PSTN and handles all billing and payment. Jajah integrates with  a number of address books and also Outlook. Jajah has also added convenient buttons that can be added, for example. The recipient clicks the button to call the sender. Jajah is also one of the EBT Accelerator companies.

Amobee http://www.amobee.com/main/hp.htm … Amobee is both a software company and a business development and sales service. They provide a  comprehensive set of offerings for mobile operators, application developers and agencies. For mobile operators, Amobee provides a telco-grade ad serving platform. For developers they provide an SDK which allows the application to be subsidized by contextual ads and access to agencies and advertisers who will place them. For agencies, the platform provides campaign management services and a catalog of mobile inventory

Silent Communications. http://www.silentcom.com/ … Silent communications provides features likely to be attractive to carriers who want to increase call completion by providing   multiple ways to respond to unanswerable voice calls. For example, if you receive a call while in a meeting you can silently send a voice reply that suggests you begin a SMS session. You can also carry on a silent voice conversation using a set of predefined responses or statements.  The opportunities here are endless :-)