With the start of FP7, there is a new instrument, the so-called Specific International Cooperation Actions - SICAs. The proposal template is identical to a STREP (ICT) or small and medium scaled focussed project (elsewhere). A SICA in fact just has a special eligibility criterion.

The special eligibility criterion for SICAs is that instead of the usual rule of at least three mutually independent partners from three different Member of Associated states, a SICA requires just two Member or Associate state partners, but then also two mutually-independent partners from two different countries in the region being targeted for international coop

Apart from these special SICA actions, partners from elsewhere in Europe or overseas can always participate in any other project, provided the minimum three EU/AS partners are in place. And if their country is listed in the Workprogramme as an International Cooperation Partner Country they are funded for their participation on exactly the same basis as an organisation in a Member state. (Organisations in non-listed overseas countries can exceptionally be funded if their participation is essential to the project - there is a section in the proposal Part B where they are invited to explain about this).