ESTA is here.

If you're planning to travel to the USA from now on for any affiliate conferences then make sure you're registered with ESTA, else you could face being turned back at the airport, this new system applies to all nations that previously didn't need a Visa and filled in an entry card on the plane. Canadians do not need to apply, there is a full list of applicable nations on the ESTA site.

Until now, registration has operated on a voluntary basis but it will become compulsory for all travellers from 12 January 2009. An ESTA, once obtained, will be valid for a period of two years, or for the validity of the traveller’s passport (whichever is shorter).

ESTA can be found here

From a personal stand point, this is great news, means I don't have to waste 4 months and a 4-5 hour trip to the US Embassy here to find out whether I need to go get a ticket! Wonder if I'm the only person who thinks the new system is great.