Probably the closest thing to what you want is to get an unblocked UK triband and let those in the UK contact you on that. It would be on roaming tariffs, and could be quite expensive for both you and your caller in some cases. Your US friends would have to place an international call to your UK number, etc. Practically speaking, you can't really do what you want, that is have just one world number, good everywhere. The best solution, in my view, is to get a long expiry pre-paid US SIM, and use that number, for both US and UK friends whilst in the US, and a similar UK SIM in the UK. Best I know of, and that's what I do. I hope this helps.

I'm a Brit now living in the US and go back to the UK about twice a year. I have a US cell phone but it doesn't work in the UK, this is work cell phone so I don't have an option to upgrade the service. I want to get a prepaid cell phone so that I can give everyone (personal rather than work related) 1 number to call me on whether I am in the US or UK, rather than having to swap out SIMS and give people different numbers.

Has anyone else done something similar or could recommend a provider (and a suitable phone - tri-band? ) that I could use for this.

thanks