According to KC, the Bulls worked out PG Jonny Flynn, who's mocked to go slightly above their draft selection. This matches some of the rumors of the Bulls possibly looking to move up though it's hard to imagine them doing so for a PG prospect. Probably just covering their bases.
What's more interesting perhaps is that Flynn would bother working out with us. The Bulls can easily bring in 60 players (or basically everyone worth drafting) before the draft, but a player won't have time to workout for every team. The bulls have the right pick to get Flynn if he slides, but they are certainly a horrible fit for him if he wants his career to go anywhere.
Patrick Mills, a possible selection at #26, was also in the workout. The Bulls also had Chase Budinger, another guy who's got good upside at #26, in for a workout.