the german prepaid SIM provider ORTEL now provides a new EU package called "cross"
it cost 20 Euro / 30 days and offeres
300 minutes to/from all EU countries + switzerland and 750 MB of data @ 7.2 Mbit in all EU countries + switzerland.
additional 500 MB can be added for 9€
(list of all countries covered: Belgium, Bulgaria, Denmark, Germany, Estonia, Finland, France, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Austria, Poland, Portugal, Romania, Sweden, Switzerland, Slovak Republic, Slovenia, Spain, Czech Republic, Hungary, Cyprus)
details:
http://www.ortelmobile.de/crosseurope.html