Here is a PHP code. I haven't tested it as I wrore it using my pda as I am making the post right now. I will try and test it later if it doesn't work properly.
PHP Code:
<?php
$site[1]="<a href='http://www.bobssite1.com'>Bobs1 Site</a>";
$site[2]="<a href='http://www.bobssite2.com'>Bobs2 Site</a>";
$site[3]="<a href='http://www.bobssite3.com'>Bobs3 Site</a>";
$site[4]="<a href='http://www.bobssite4.com'>Bobs4 Site</a>";
$site[5]="<a href='http://www.bobssite5.com'>Bobs5 Site</a>";
$site[6]="<a href='http://www.bobssite6.com'>Bobs6 Site</a>";
$site[7]="<a href='http://www.bobssite7.com'>Bobs7 Site</a>";
$site[8]="<a href='http://www.bobssite8.com'>Bobs8 Site</a>";
$site[9]="<a href='http://www.bobssite9.com'>Bobs9 Site</a>";
$i=0;
while($i<4){
$whatsite=rand(1, 9);
echo $site[$whatsite]."<br>";
$i++;
}
?>