TITLE: What math institutes offer research in pairs/research in teams?
QUESTION [47 upvotes]: Some math institutes offer programs in which a small number of researchers are enabled to meet at the institute for a week or more.  A list seemed as if it could be useful.

REPLY [5 votes]: The Centro di Ricerca Matematica Ennio De Giorgi at the Scuola Normale Superiore of Pisa usually has a program of research in pairs: 
http://crm.sns.it/visit/pairs.html