Technical Questions: Will the phone work in my country?

Within the United States and Canada, the majority uses only GSM 1900 bandwidth. In UK, Australia and most parts of Asia with the exception of Japan and South Korea, their networks use GSM 900 / GSM 1800.

Here are the country's ranges for your reference:

Quad Band GSM 850/900/1800/1900 WCDMA
Europe, Asia, Africa, North America, South America, New Zealand and Australia

Tri band GSM 900/1800/1900 +UMTS
Europe, Asia, Africa, North America, South America, Australia, and New Zealand

Dual band GSM 900/1800
Europe, Asia, Africa, South America, New Zealand, and Australia