With the present exchange rate, $100 ($92 if you buy from cheapphonecards.com and use their coupon code) is what, 40 pounds? For a thousand minutes and one-year validity, no less. Remember to register with my.t-mobile.com while in the US, so you can easily top up each year while overseas, where the SIM won't work (at present).

I think 911 taxes also make the concept of the never expiring card very difficult. I'll tell you, however, this is an area that I have my eye on Yackie. If they can pull off the US MVNO, it will be a nice package for many people.

There are some fees and assessments that the government requires that actually cost the carriers a few bucks per line, per month.

Another reason is that US numbers are, or used to be scarce, due to the fixed number of digits and geographical location of the numbers. This means that, unlike elsewhere, a carrier cannot simply add another digit or come up with another prefix and create another hundred million theoretical subscriber numbers. With area codes running out of numbers in the US, a phone number has a theoretical value itself. However, recent changes, particularly assigning unused numbers to carriers in smaller blocks, have freed up capacity and reduced the pressure for more area codes.

Thanks guys. All this is very interesting, and could also help to explain why many of the USA DID's that used to be free are now charging monthly fees. (e.g. Voicestick)

This is a PS, kind of sort of. TMobile's Hotspot at Home works with prepaid SIMs. The calls are not free. They are billed the same as if they are made on the prepaid network, but for someone trying to manage a US sim from abroad, this would give you limited access to the account/sim from your home country.

Hotspot at Home is TMobile's brandname for its UMA set up which is GSM over ISPEC, a non-SIP based form of VOIP.

Stu

Maxroam and others are working on this too

So, while H@H costs the postpaid customer a flat $19.99/month; the prepaid customer just needs a UMA phone? While I think I'd probably set up my WiFi phone's VOIP to use my now outbound-only Voicestick account, I can also see where using a prepaid for UMA calls overseas might work pretty well.

With the exception of the new wi-fi Blackberry, TMobile's UMA handsets have a hardtime logging on to non-TMobile handsets. The browsers won't handle wi-fi until the UMA tunnel is established and you can't establish the UMA tunnel until negotiate the wi-fi login.

It is also worth stressing that UMA is not your standard SIP VOIP. A SIP based phone (e.g. the Nokia E Series) won't handle UMA or Vice Versa. The HP Communicator may be able to handle both. That is the only one I know of.

Going back to my original request, and after reading between the lines of what Yackie, maxROAM and now even UM are saying (and people here have been saying too) it looks like all of these will be offering cheaper US in/out in the next 3 months anyhow. My trips aren't for a while anyhow, so it looks like I will just stay put for a little while and not buy a T-Mobile SIM just yet.

Let's see what comes out of these guys. Not too sure if it will be dual IMSI or some other technology but if they can figure something out for us to get anything in the region of 10c-15c/min with a local USA DID that I can activate for whilst I am there only, I think that will solve not only mine but most travellers needs.