The folks at Talkster came out of hiding this week, introducing the alpha version of their new Mobile VoIP service.

The solution leverages both VoIP and cellular networks to provide what the company calls a consolidated communications service that supports "clientless calling" -- with no fees, no subscription to buy, no software to download -- and it works on any mobile network with a data plan. International calls, though, do incur a charge.

Talkster enables mobile voice over IM calls (via Google Talk, Gizmo Project and MSN Messenger) on just about any phone. Most impressively, without installing anything on your phone or PC, it's able to display full presence information on all your contacts.

There are other companies doing various things like this, like PeerMe or JAJAH, but Talkster contends that nobody else supports so many different VoIP and VoIM solutions, can operate on all types of mobile networks -- and actually works.

A public beta is planned for this fall -- you can sign up for the beta at their site.