What Should I Know About Traveling Without a Visa in Thailand?

I just want to thank everyone for answering my mild, in the whole scheme of things, questions. I've been here for three months without a visa and am headed home in about a week. One trip to Singapore, one visa extension, on trip to Bali (have a friend there) did it - although you had me paranoid enough that I carried 20,000 Baht with me on that last trip. You were always willing to answer the simplest questions and were supportive. And I'll be better prepared because of you when I return.