After reading through this forum I am surprised http://www.sipgate.co.uk has not been mentioned, other than one post I made, unless I have missed them.

Sipgate offer a VoIP service and issue you for free, a geographical number of any area of your choice.

You can make free calls to other Sipgate users and many other VoIP networks, the big plus point is the fact you get a real telephone number anyone can call you on, and you do not have to choose a local area code.

I find 1899's VoIP and Sipgate to be a great combination.

I HAVE TRIED TO REG WITH SIPGATE,
After filling in the form and given only one number to choose from , then clik to submit iam told the number is invaliid,
what could be wrong, any one help please.

It could be their non-coherent cookie mandate? I had the same problem.

The difficulty is that some sites configured by inexperienced nurds mandate separate and sequential cookies for every disparate page. With more intellegent browsers like Firefox this locks you out, if you do not set your configuration to accept the very worst that anyone can throw at you without question! I never allow this configuration on principle and because there is significant evidence to show that undesirable sw elements may be spread without control to your PC if you do!

I think if you take slightly too long to fill the details out, you get this error.

Some area codes, yes you only have one choice, others like London, Liverpool and Birmingham you have a greater choice of number.