Following my return to Chiang Mai yesterday and having heard contradictory info re submitting a TM30 for someone only on a visa exempt 30 day stamp - i went to the immigration office by the airport today. It is open on Sundays for TM30 reporting. Done downstairs - a single officer asleep behind the counter - a slight difference from weekdays! I showed her my passport stamp and asked if i needed to do a TM30 - she simply took the passport from me clicked a few buttons on her computer screen, filled out a slip of paper and stapled it to my passport. (I am already on their 'system' so no photocopies or other details required). So it would seem that they want a TM30 completing for short stay tourists as well.