We just added full support for SMS in Canada[0], have local voice-enabled numbers in the UK, many more European countries on the way[1] and international SMS in beta[2]. If we're not where you need us, most likely we're working hard to be there as soon as it's possible.
If you have a phone number you want to use to make calls from in a country we don't offer local numbers, you can verify it to use as a caller ID then call to any of our supported countries[3].
Thanks. For what it's worth, I'm in India - I know the bureaucracy around here will make it tedious - but on the other hand, everyone has a mobile phone and sms is very popular (and cheap) - the market for phone-based apps is potentially very huge.
We haven't announced any formal plans for expansion to Asia, but we are committed to serving developers worldwide. We'll make sure to let everyone know when we have plans we can share.
If you have a phone number you want to use to make calls from in a country we don't offer local numbers, you can verify it to use as a caller ID then call to any of our supported countries[3].
[0] http://www.twilio.com/CA/pricing [1] http://www.twilio.com/eu-beta-signup [2] http://www.twilio.com/faq/international [3] http://www.twilio.com/pricing/international-calling-rates