Nice, although I doubt it would be released here, I remember having an old Nokia modded to use dual SIM cards.
FYI the carrier locking is only heavy in the US from what I have seen. Most places I traveled there's a larger preference for unlocked phones, and there easier to pick up.
[citation][nom]ikyung[/nom]Most likely if you are using a dual SIM phone, you will use one for a carrier, and the other for a prepaid for when you travel or something of that situation.[/citation]
That's what I did

it also works to have a provider that's cheaper in your home town, and then getting a second pre-paid from a more expensive company, that has better service, when visiting the Provence.