If you're displaying on an ANSI terminal, you can also use Term::ANSIScreen to move the cursor around. Here's a sample that clears the screen, prints "Hello" at column 10, row 10, pauses, then prints "Bye" on the same line.

use strict;
use Term::ANSIScreen qw(:cursor :screen);
$| = 1;

cls;

locate(10, 10);
print "Hello"; 
sleep(1); 

locate(10,10);
clline();
print "Bye"; 
sleep(1);
[download]

Update: Turned off buffering (which was causing some problems) and added example for clline.

stephen