In Condé Nast Traveler's December issue, writer Boris Kachka has done the (sometimes embarrassing, sometimes quite costly) work to find out the who, what, where, when, and how of giving gratuities in 26 countries. Below, some tipping snippets from Jordan. For more, check out the December issue, on stands now.

At Restaurants: Service is almost always included in the bill; add 5-10 percent for the waiter.
At Hotels: One dinar ($1.50) per bag for the porter, same per night for the housekeeper--or a bit more, as they tend to be impoverished Palestinians. Tip the concierge--in advance--only if you expect something very special to be done, like access to rare tickets.
Guides and Drivers: Ten to 15 percent for taxis; $30 per person per day for tour guides; private driver, $30 per day total.
Anyone Else? Bedouins in Petra--a tribe called Nabateans--control most tourism to the ancient city--part of a deal worked out with the king when the city was made tourist-friendly. They will sometimes keep asking for tips--even after you've already paid. It's okay to decline firmly.
Dollars Accepted? Yes, and euros, too.
Note: Ask whoever arranged your guides--local or government-sanctioned--whether the tip has been prepaid. If so, refuse to pay more.

Further reading:
* Tipping Guide: Brazil and India
* Etiquette 101: India
* A Conversation with Jordan's King Abdullah II
* Women of the World: Queen Rania at Condé Nast Traveler's 2008 World Savers Congress
* How not to embarrass yourself in China
* Quiz: Test your Mediterranean etiquette smarts