Cellphones connect to SPA-3000 and make use of free minutes?

[svkhtn]

Hi,

I noticed that there were a couple of people asked about how to forward calls using the free minutes from your cellphone.

For example, if someone wants to ring a cellphone number, he/she can ring to my VOIP account on SPA-3000, and then SPA-3000 (which connects to my cellphone, instead of PSTN line) forwards it out to any other cellphone that he/she prefers.

==> take avantage of free minutes or same network calls on cellphones.

I think:

1. As others suggested, use a Dock-n-Talk to connect to the PSTN line of the SPA-3000. I dont know about Dock-n-Talk. Is it cheap? How is the compatibitiy (i.e. what type of phones etc.)?

Edit: I just found it here: https://www.phonelabs.com/purchase.asp
Hmm... not very cheap though! I also need to purchase the correct cable for my phone as well.

2. My initial idea is to have something which can insert a mobile SIM card in and output a RJ11. I checked on google and found "GSM gateway" (e.g. http://www.voip-info.org/wiki/view/VOIP+GSM+Gateways ) will cover my need. Does any of you use this solution? What is your experience? Any recommendations?

I am wondering if there is any other solutions to this?
Which option do you think best?

Thanks,
SV