Place a block in multiple regions
Multiblock module makes this possible:


  Drupal's block module is limited by the fact that a block can only
  have one instance. Each block has a 1:1 relationship with its region,
  weight, visibility (and other) settings. This means that it is
  impossible to have blocks in multiple regions or to have blocks that
  have different settings on different pages. MultiBlock module solves
  this problem by allowing you to create multiple Block Instances of
  already existing blocks.