Top cat

Hi I hope someone can help us, as part of our round the world trip we are arriveing in Thailand in May 2010 and flying out of Thailand in Febuary 2011.We want to visit other countries in southeast aisa in that time.As we understand it the rules have changed if we cross by land into another country we may get a 15 day visa coming back into Thailand but we will be flying back in and I think then we will get a 30 day visa.How many times can we do that or if we get 60 days visa do we have to stay out of the country for 60 days before we can reenter the country.We are both over 50 so we may be able to go for a long stay visa. We would be grateful for any sugestions. Top cat