A passport is required which is valid for at least 6 months after your intended period of stay although a visa for EU or USA nationals is not required unless you intend staying for a period of over 3 months.
The Swiss Embassy should be contacted for matters regarding visas, work permits and immigration. It can be found at:
Embassy of the Swiss Confederation 16 - 18 Montagu Place London W1H 2BQ Tel: (020) 7616 6000 (020) 7 331 313 (recorded visa information charged at 50p/min). Fax: (020) 7 724 7001.
While in Britain you can find UK representation at the Embassy located at:
British Embassy Thunstrasse 50 3005 Berne Switzerland Tel: + (41) (31) 359 7700 Fax: + (41) (31) 359 7701 email: Information@british-embassy-berne.ch
There are also British Consulates in Geneva, Montreux, Vevey , Valais, Zurich and Lugano