Hmm, if the tsunami took 2 hrs to reach Sri Lanka and 3 hrs to reach India...

No, the current runs sliently until it hits the shelf. India could have figured it out, but these people don´t have phones, left alone TV´s and stuff. They are poor.

[link to starbulletin.com]

"Charles McCreery, head of the Ewa Beach facility, said the center tried frantically to alert countries in the Indian Ocean area about the oncoming waves but telephone numbers of appropriate officials in some countries were not immediately available. It did send an alert to 26 countries participating in the emergency warning system, including Thailand and Indonesia, within 15 minutes of the earthquake. India and Sri Lanka are not members."

"Couldn´t somone at a major seismographic facility (say, USGS) have phoned Sri Lanka to warn them?"

Yes, we could have warned government officials but these countries lack the infastructure to warn all the communities involved. It´s also possible that due to a lack of sensors in that region of the world that the USGS didn´t know the tsunami was going to happen or be that big because not every offshore earthquake causes a tsunami, although large ones generally do.