As Thomas pointed out, Switzerland is not in the EU along with Norway, Iceland & Leichtenstein (all EFTA members), and the small nations of Andorra, San Marino, Monaco & the Vatican.
But when it comes to immigration formalities, travel between Switzerland & EU nations are often treated like intra-EU travel. Most Swiss/EU airports have separate lanes for EU/EFTA passport holders, and a separate one for other passports. Both Switzerland and EU nationals still need to present at least a national ID
(most EU countries have it, but not the UK) or a passport. Immigration officers often never bother to check the passport pages, usually flashing your passport cover to them is sufficient. Even for a Malaysian passport holder like myself, my passport hardly ever get stamped in GVA
during my many visits there.
I've been on a train between Denmark & Germany before and someone in my compartment did not bring his Dutch passport. The German border police was a tiny bit suspicious of him (he's not caucasian). All the police officer asked him to do was to speak some Dutch to confirm his Dutch identity. That's it
[Edited 2004-11-06 11:18:20]