I am looking for a way to make UK phone calls to other mobile users (and even landlines) for free via my home wi-fi connection on my n900. Currently I use my landline and it's costing too much!

Is there a way for n900 users to do this? Google Talk? Skype? Viber? Nimbuzz?

Thanks

At the very minimum you will be paying for the data transmitted (via your 3G or WiFi/broadband accounts) But this is minimal. Get yourself a SIP account with a local provider. I use VoipVoip who are in the UK and charge from .02 to .06 cents per min depending on where you call. Once you create an account the 'call using SIP' option is available in the dialler. Skype is integrated into the N900, you need only to add your account details. Viber calls are free of charge (excepting data) to others that have the app loaded but I haven't yet found that solution on Meamo. Hope this helps.

I have cable Broadband with Virgin Media and my router provides a wireless signal to my home so in terms of connection, it will be free because I already pay for the connection for my PC.

I wish to learn more about Skype. Can I call someones mobile phone with this? Must they have Skype installed also? Is this free?

As I understand it you can Skype another handset without it having Skype loaded but to do this you must buy Skypeout credit. Conversely a smartphone with Skype loaded acts like any other skype client and so doesn't attract a fee beyond network data costs.

Since the n900 has Skype, I just need to ensure the person I am contacting on their mobile has Skype too and then we can both perform audio chat for free (providing we BOTH have an internet connection? or just one of us?)

You both must have skype installed and internet connection and if you both have a front camera you can even make a video call, as long as you want, for free!!! did it a few times with another nokia

I am looking for ways to do so only one of us has an Internet connection. With skypeout credit, must the recipient have Skype installed on their mobile?

skype to skype is free. (you pay the internet provider)
In general, SIP to SIP (VoIP) is free.
Anything to landline is not free (except landline to landline, but this is because you allready pay your landline provider, hence, not free).
Anything to mobile is not free.

To call a mobile/landline number from skype, you need to pay.

But services like Nimbuzz and Viber allow phone users (Android, iphone) to call mobile to mobile free? and there is nothing like this for the n900?

@gohan2091,

Those programs work like Skype, you can't call "mobile to mobile free" but "<put-your-program-here> to <put-your-program-here> free".