Its available in apple stores at no commitment prices, at least in the Boston area as recently as 3 weeks ago, also at palo alto. Make sure you take some form of id, passport, India driving licence etc.
This is a no commitment deal so no question of at&t, contracts or any other complications, just pay 599 plus tax for the 16GB or 699 plus tax for the 32GB.
Its currently not available off the shelf in UK or Singapore, you have to order online and there is a 3 week waiting period, the advantage is UK/Singapore is unlocked, Canada is also unlocked and relatively cheap but I have no connections in Canada.
On the unlocking front, all new iPhone are currently 4.1 out of the box with a newer baseband, mine was 4.02 with 1.59 baseband which can be unlocked, however there was no jailbreak available for 4.02 untill geohot released limera1n last weekend. As soon as 4.2 gets released apple stores will ship those so important to do research on versions before buying.
Similarly while 4.1 is now jailbroken there is no unlock for the newer baseband in 4.1. Apparently geohot is working on the unlock for the newer baseband and it will be out soon, could be weeks.
Also for new iPhone owners please do research before doing any operation in iTunes to update software. That's how most folks get stuck. And make sure you save shsh before doing anything.