An approach described in http://www7.software.ibm.com/vad.nsf/Data/Document4359?openDocument&p=1&BCT=3&Footer=1 and also in http://members.aol.com/_ht_a/kgb1001001/Articles/PLoP99/brownfinal.pdf that describes how to use Session Beans as implementations of the Facade Pattern to reduce the distribution cross-section of an EJB system.

An EJB specific version of one of the ComponentDesignPatterns, FacadeAtTheDistributionBoundary