removing extra empty lines

[Selector, Lev Y]

Folks,

I have a long file which has many "empty" lines 
with nothing but may be spaces or tabs (/^\s*$/). 

These lines tend to group together creating chunks 
of empty vertical space on the printout. 

I want to reduce the number of empty lines 
in such chunks to 1 line.

What would be an elegant way to do this?
  
Warmest Regards, 
Lev Selector