Head on over to the BuddhaSoft section of Sourceforge.net, and grab yourself a copy.
You need SDL to compile Blocker. The SDL_image and SDL_mixer packages are also needed.
In order to compile and install Blocker on your system, type the following in the base directory of the Blocker distribution:
% ./configure
% make
% make install
Since Blocker uses
autoconfyou should have not trouble compiling it. Should you run into problems please report them to the the author at Sean Hagen