We give an introduction to the problems faced on the way to a reliable
lattice QCD computation of B-physics matrix elements. In particular various
approaches for dealing with the large scale introduced by the heaviness of the
b-quark are mentioned and promising recent achievements are described. We
present perspectives for future developments.Comment: Invited talk at the XXIII Physics in Collisions Conference (PIC03),
Zeuthen, Germany, June 2003, 15 pages LaTeX. PSN FRAT07. Updated references
and result of ref.[40
