9 The concept of aggregates is intermediate between those of arrangements and configurations. It deals with interrelations of points and lines, in the Euclidean or the projective plane, and has variants that deal with pseudolines. In contrast to arrangements, aggregates admit duality; in contrast to configurations, there are much less rigid requirements. Although the terminology is new, aggregates have a long history, starting with "orchard problems" some two centuries ago, and later with the "Sylvester problem" of "ordinary" lines or points. Other relevant results are those of Salamon-Erdös on number of points determined by n lines, and results on "omittable" points. The talk will survey these results, and present new ones. Bled'07 Branko Grünbaum Grünbaum grunbaum@math.washington.edu Branko Grünbaum Grünbaum grunbaum@math.washington.edu <MaKaC.conference.ContributionType object at 0x2aab1d3b1320> MSCONF