Since the 1930s assisted suicide has been legal in Switzerland, where the activities of the Dignitas clinic have made international news.
Here are some links to information on the situation in Switzerland:
Assisted dying is illegal in most other countries (12 Dec 2005)
Britons who chose assisted suicide (24 Jan 2006)
Dignity...in a car park? (1 Dec 2007)
What's in a name? A look at the Dignitas 'clinic'... (7 Nov 2008)