Since all the other threads are about should you or shouldn't you & usually get into a philosophical discussion, thought I'd post something I read in newspaper that was taken from Magellen's. It's a more specific guide by country.
REGIONAL TIPPING TIPS
Asia/the Pacific: Special care must be taken to ensure that your well-meaning gesture is not taken as insulting. If you are unsure, it is best not to tip. If possible, observe the locals and follow their lead.
Europe: Many hotels and restaurants add a service charge to the bill. In most cases, an additional tip is unnecessary. If no service charge is added to your bill, 10% is the general rule for restaurant service, and $1 per bag for a hotel porter.
Middle East/Africa: While your tip will not be seen as insulting, it may be unnecessary. Once again, the best bet is to do as the locals do.
Central/South America: Many hotels and restaurants add a service charge to the bill, and an additional tip is unnecessary. If not, 10% is the general rule for restaurant service, and the equivalent of $1 per bag for a porter.
FOREIGN TIPPING GUIDE - COUNTRY
This list is by country, and then waiter/waitress, porter, and taxi driver categories.
Argentina
W/W: 10%
P: $1
TD: Round up taxi fare or small tip
Australia
W/W: 10% in fine restaurants only
P: $2 per bag
TD: Round up
Austria
W/W: 5% plus service charge
P: $1 to $2 per bag
TD: Round up
Bahamas
W/W: 10%
P: $1 per bag
TD: 10%
(15% actual per local FTer
Belgium
W/W: 10% if no service charge
P: $1 per bag
TD: Round up
Brazil
W/W: 10% to 15%
P: $1 per bag
TD: 10%
Brunei
W/W: None
P: None
TD: None
Canada
W/W: 15%
ranges from 10%-20% per local FTers
P: $1 to $2 per bag
TD: 10%
Cayman Islands
W/W: 15% if no service charge
P: $1 per bag
TD: 10%
Chile
W/W: 10% in addition to service charge
P: $1 per bag
TD: None
China
W/W: 3% in major cities (
according to local FTers; 0%)
P: $1 to $2
(according to local FTers, none)
TD: None
Colombia
W/W: 10%
P: 75 cents per bag
TD: None
Costa Rica
W/W: None
P: $1 per bag
TD: 10%
Czech Republic
W/W: 5% to 10%
P: $1 per bag
TD: Round up
Denmark
W/W: None
P: $1 per bag
TD: Round up
Ecuador
W/W: 10% if no service charge
P: 75 cents per bag
TD: None
Egypt
W/W: 5% to 10% plus service charge
P: $1 per bag
TD: Round up
Estonia
W/W: 10-15% for restaurants (in pubs toss spare change into big shared bowl for waitresses)
P: ?
TD: ?
Fiji
W/W: None
P: None
TD: Round up
Finland
W/W: None
P: None
TD: If you pay by credit card - none. If you pay with cash - none if you don't want to, but rounding up is acceptable to avoid hassling with coins.
France
W/W: 5% to 10%
P: $1 per bag
TD: Round up
Germany
W/W: 5% to 10%
or round up plus euro or two per some FTers
P: $1 per bag
TD: Round up
Greece
W/W: 5% to 10% plus service charge
P: $1 per bag
TD: Round up
Hong Kong
W/W: 10% plus service charge
if svg charge no need to add 10% per local FTer or round up
P: $1 per bag
TD: Round up
Hungary
W/W: 10% if no service charge
P: None
TD: Round up
India
W/W: 10% if no service charge
P: $1 per bag
(according to local FTers 50cents/bag)
TD: Round up
Indonesia
W/W: 10%
P: 50 cents
TD: Round up
Ireland
W/W: 10% to 15%
P: $1 per bag
TD: Round up
Israel
W/W: 12% to 15% if no service charge
P: $1 per bag
TD: 12% to 15%
(according to local FTers, tips included in fares; could tip but not 12-15%)
Italy
W/W: 10% plus service charge
P: $1 per bag
TD: Round up
Japan
W/W: None
P: None
TD: None
Malaysia
W/W: None
P: None
TD: None
Mexico
W/W: 10% to 15%
P: $1
TD: 50 cents
Morocco
W/W: Leave loose change
P: 50 cents per bag
TD: Round up
Netherlands
W/W: 5% to 10%
P: $1 per bag
TD: Round up
New Zealand
W/W: None
P: None
TD: None
Norway
W/W: 10% if no service charge
P: $1 per bag
TD: Round up
Oman
W/W: None
P: None
TD: None
Peru
W/W: Up to 10% for special service
P: 75cents per bag
TD: None
Philippines
W/W: 10%
P: 50 cents to $1 per bag
TD: Round up
Poland
W/W: 10%
P: $1 per bag
TD: Round up
Portugal
W/W: 10% to 15% if no service charge
P: $1 per bag
TD: Round up
Romania
W/W: Round up bill
P: $1 per bag
TD: Round up
Russia
W/W: 10% to 15%
P: $1 per bag
TD: Round up
Samoa
W/W: None
P: None
TD: None
Saudi Arabia
W/W: 10% to 15%
P: $1 to $2 per bag
TD: 10%
Singapore
W/W: None
P: None
TD: None
South Africa
W/W: 10% if no service charge
P: 50 cents
TD: 10%
South Korea
W/W: None
P: None
TD: None
Spain
W/W: 7% to 10% plus service charges
P: $1 per bag
TD: 10%
Sweden
W/W: 10% if no service charge
P: $1 per bag
TD: Round up
Switzerland
W/W: Round up
P: $1 per bag
TD: Round up
Taiwan
W/W: 10% if no service charge
(none according to local FTer)
P: $1 per bag
TD: None
Tanzania
W/W: 10%
P: None
TD: None
Thailand
W/W: None
see post # 32 in this thread for update by local FTer
P: None
see post # 32 in this thread for update by local FTer
TD: None
see post # 32 in this thread for update by local FTer
Turkey
W/W: Round up
P: $1 per bag
TD: Round up
United Arab Emirates
W/W: None
P: None
TD: None
United Kingdom
W/W: 10% if no service charge
P: $1 per bag
TD: 15%
(according to local FTers 10% or round up to nearest pound)
USA
W/W: 15% to 20%
P: $1 to $2 per bag
TD: 10% to 15%
Venezula
W/W: 10%
P: 75 cents per bag
TD: 10%
Vietnam
W/W: None
P: None
TD: None
So far the China listing is the only one that seems to be causing any controversy, so overall I think the list will be helpful for FTers & beats folk having to 'guess'. Brunei now spelled correctly. 
