Curious, what does this have to do with 3rd World Traveling? I'll respond anyways.
I disagree. Tipping should be based upon local customs and courtesies.
In the US, to be safe just tip everyone, everyone else does. (Waiters, Bartenders, Valet, Bellhop, Housekeeping, coat check) 10-15%!
But in Japan, people don't tip. I've even heard that some of the servers will get a percentage of the business they did that night from the restaurant. Not so sure about that. You could offend by tipping.
Some coutries it's illegal to tip. I just found this, but you should always check local customs.
Double-check the tipping protocol at South Pacific and Asian hotels. Many prohibit tipping to prevent staff from hustling guests for money.
COUNTRY GRATUITY PROTOCOL
Australia and New Zealand
Round up taxi fares and restaurant bills to nearest dollar.
Service charges generally included in bill.
Britain and Ireland
Service charges usually included in restaurant bills; otherwise, standard U.S. tipping rules apply.
China and North Korea
Tipping is illegal.
Round up the bill to nearest koruna.
France and Germany
Service charges generally applied to bills; customary to add 5 percent extra.
Tipping is common--about 10 percent in most situations--even when a service charge has already been applied.
10 percent tip is customary.
Service charges are usually included in bill.
Restaurants and hotels typically add 10 percent service charge to bills; otherwise, tipping not expected.
Tipping is customary, about 10 percent, even when a service charge is already included.
Tips are usually included in hotel and restaurant bills; otherwise, tipping is not expected.
Tipping is expected for porters and room service.
Tipping is customary, about 10 to 15 percent. Service charges rarely applied.
10 percent tip is common for most services.
Tipping is not expected.
Offer a 10 to 15 percent tip even when service charges have been added.