In a referendum, 55 percent of Swiss voters who went to the polls cast their ballots in favor of joining the Schengen agreement. Implementation will last through 2007 (though it will be complete for the 2008 European football championships, co-hosted with Austria), but the path to passport-free travel is clear. Joining the area also gives Swiss authorities to a collective database on wanted and missing persons.
Norway and Iceland are the other two non-EU members of the Schengen agreement. The rest of the old EU-15 are members, except for Ireland and the United Kingdom.
UPDATE: As Edward writes, and I should have mentioned, “It is also interesting to note that the supposedly ‘socially conservative’ Switzerland has become the first European state to give solid legal rights to gay partnerships in a popular vote. This should also put some of the recent EU referendum in some perspective.”