I've done this before but can't remember the solution.  I have two columns of
date: Column A contains first names, Column B conains last names.  I created
column C for the combined contents of A and B.  I also want the data
separated by a space.  I understand that if I want to combine the contents of
two cells, I could use the formula  =A1&" "&B1.  But how do I do this for
entire columns with a range of approximately 1,000 cells?

I am not a heavy user of excel, so please keep the answers simple.  Thank you.