PS. Does anybody know if a VISA to the US is required for citizens of the European Union countries (like Sweden)?
Nope.
Check out: http://www.ins.usdoj.gov/graphics/lawenfor/bmgmt/inspect/vwpp.htm
Most importantly: What Countries Are in the VWP? The following countries are currently in the program: Andorra, Argentina, Austria, Australia, Belgium, Brunei, Denmark, Finland, France, Germany, Iceland, Ireland, Italy, Japan, Liechtenstein, Luxembourg, Monaco, the Netherlands, New Zealand, Norway, Portugal, San Marino, Singapore, Slovenia, Spain, Sweden, Switzerland, The United Kingdom*, and Uruguay.
-James