From what I am reading about it - it sounds really great - especially if you've got a free incoming plan. It's a device that you plug in to you voip phone (or you home phone if it has 3 way calling) at your home site. You can then set it up so that you call it and hang up after one ring. It will call you back (free incoming) and then allow you to dial another number that it will conect you to using your home phone's 3-way calling feature. Whatever rates you have on your home phone is what you pay. If you've got free long distance or free international at home - the call will be free. You can realize benefits from other phones besides your cell phone. Even if you don't have free incoming but you want to make an international call at your home phone's rate - you can use this.
Magicjack with Dialmate .
I was referring to services where you use your cell phone to call a number or send a text to a number, then the service calls you back, then you are connected to the number you wanted to call. That way your cell phone is on an incoming call instead of an outgoing call.
The third party service then charges you for the time (as low as 1 cent per minute), instead of your cell phone company (as high as 50 cents per minute, expecially if you were calling long distance). It works great if you have free incoming calls on your cell phone.
Dialmate basically sets this up so that you can use your own home line or VOIP line to do this, instead of the third party service. But since Dialmate costs $269, and the third party service bills 1 cent a minute, there's not much benefit.
If you have GrandCentral and your cell has Web access, you can trigger a call and GC will ring your cell and then call the desired destination number. No charge.
Otherwise, try Future Nine. They have an ANI callback feature -- call a trigger number and F9 calls you back. You then enter your destination number and the call is placed. You pay for both legs of the call, but the rates are very reasonable, $0.01/min. to the US, so a US to US call would run you two cents per minute.