http://grantland.com/features/mlb-transaction-trees/ The longest chain of trades to go from a current player into the past. I'm thinking our longest is Lillard, since his pick was part of a trade...
The Eddie Gill-->Viktor Khryapa-->Lamarcus Aldridge chain goes back a few months farther than the Przybilla portion of the Lillard chain. I'll keep looking at the rest of the roster for anything older than Feb '04.
http://espn.go.com/boston/nba/story/_/id/8184923/boston-celtics-acquire-courtney-lee-sign-trade-deal So...nothing (capspace) --> Sasha + 2 second round picks -->Withey --> Rolo. This one might be my favorite.