Central America - Do I need a visa or tourist card for Panama?

I am going to visit Panama January 11-17, 2009. I have a valid passport but have read conflicting reports about what else, if anything, is needed for entry. Some sites say US nationals need a visa. Some say a tourist card. I called DL international desk (I have a DL ticket) and even they didn't know. Anyone here know?

Visa required, except for Those coming strictly for touristic
or business purposes and holding a stamped visa or a Tourist
Card valid for 30 days, issued to nationals of U.S.A..

NOTE 31855: Tourist Cards can be issued by airport offices
or airlines against payment of USD 5.-, or equivalent,
provided holding normal passports.

According to http://www.migracion.gob.pa/eng/servicio.php?cont=paisvisa which is linked to on the Panama Embassy website a US Citizen can have a Stamped Visa OR a Tourist Card

Stamped Visa:
This visa does not require a previous authorization from the National Directorate of Immigration and Naturalization. The applicant can request it within his/her country before the Panamanian Consulate. This is a Tourist Visa and the Consul decides the length of time granted to the applicant. Only after that, the person can travel to Panama.

Tourist Card:
The citizens from countries that are allowed to travel to Panama with a tourist card do not need a visa, they only have to buy a tourist card within the airline, which cost is $5.00, fill it out it with the requested information and present it along with the passport when entering Panama. From here originates the importance of the migratory classification established by the Ministry of Foreign Affairs. If the person is a citizen from a country which is required to hold a stamped visa or a tourist card to come into Panama, this means that the person has two options, which are: to apply for a visa before the Panamanian Consulate within his country and travel with the stamped visa on his passport, or to buy the tourist card from the airline or at his arrival at the country. If the person is a citizen from a country which is classified as one that requires a stamped visa, it has no other option than to previously request a stamped visa at the Panamanian Consulate before travelling to Panama, and if the person is a citizen from a country that requires an authorized visa, the visa application requires the previous authorization of the National Directorate of Immigration and Naturalization. In all cases, it is required to comply with all the requirements to come into the country, (economic solvency, passport with a six month minimum validity and return ticket for his country.

It's very simple. There will be a guy sitting behind a little desk/podium before you get in line for immigration (It's hard to miss). Pay him and he'll hand you a tourist card to fill out. Hand it along with your passport at immigration and you're good to go.

This is providing your a just a tourist visiting for a short time, of course.

Thanks to all who responded. Looks like all I'll need is my US passport and $5 to pay to some guy sitting at a desk at PTY!

Just an update—recently got back from PTY. When I gave my boarding ticket to the agent while boarding the plane in ATL the agent wanted to know if I had the tourist card. I said no. She said I should buy it at the ticketing desk in the gate area for $5 which I did. I had to show it in PTY but no one ever took it.

I which I had found this forum sooner and would have told you what to do. I would have said that a tourist card would suffice along with your US passport. You could buy at the airline desk if they have but most of the time it's offered at the gate for 5 bucks. Sometimes whenever you are running from one gate to the other and they are already boarding there is just no time. So the next thing is to buy it when you get to Panama and go down the stairs to immigration and yes, there is a guy/girl or both at a booth to your right at the bottom of the stairs. Sometimes the only problem is that there is a lot of people buying it too but the line goes pretty fast. The airport in Panama is more efficient than it ever was. A few years ago I had to chase someone down for a tourist card as there was no booth. ;)