I'm taking my first trip the beginning of October. Trying to figure out what to do about money. Should I convert my money before I go or wait until I get to Cancun? If I wait, where is the best place to go to do this? I'm hearing from some to forget about traveler's checks--it's just not practical there. Is that true? Is it best to just have enough cash for tips and then use a card for the rest? Any suggestions would be greatly appreciated.