They advertised last week that they were going to have L&O episodes with Soprano cast members all week this week. Yesterday they had Michael Imperioli taking Green's position for a while. I know Edi Falco is in an episode as well.
TIS
"Mankind must put an end to war before war puts an end to mankind. War will exist until that distant day when the conscientious objector enjoys the same reputation and prestige that the warrior does today." JFK