For everyone’s information.
Thailand new six-month, multiple-entry tourist visas is now in effect which allows unlimited border crossing within the validity period. The visa costs Bht 5,000.
However, each entry will be limited to 60 days. The visa can be extended inside the country for up to 30 days for an additional fee.
You may apply for this visa at any Thai consulate in any country. No information yet if you can apply for it upon arrival in Thailand.