In place editor for blocks
There is the Boxes module. Which supports in-place editing.


  Boxes module is a reimplementation of the custom blocks (boxes) that
  the core block module provides. It is a proof of concept for what a
  re-worked block module could do.
  
  The module assumes that custom blocks are configuration, and not
  content. This means that it is a reasonable action to ask for all
  blocks at one time, this is in fact exactly what the core block module
  does.
  
  Boxes provides an inline interface for editing blocks, allowing you to
  change the contents of blocks without going to an admin page.
  
  Boxes provides exportables for its blocks via the (required) Chaos
  tools module. This allows modules to provide blocks in code that can
  be overwritten in the UI.
  
  Chaos tools is required to use Boxes.


Be sure to look at the module page for full information.