No, I'm not talking about ironing cloths, more talking about my very own algorithm. It's not that special and seems to produce a lot of duplicates, and is quite reversable (credits to sraeG for reversing it in a challenge). I might write a completely new one, more advanced maybe. Source code is in PHP:

function iron($nr,$method = 'numeric')
{
$chrs = preg_split('//', $nr, -1, PREG_SPLIT_NO_EMPTY);
$d = '';
foreach($chrs as $c)
{
if(substr($d,-2,2) == round(ord($c)/2))
{
$d .= round(ord($c)/2)*round(ord($c)/2);
}
else
{
$d .= round(ord($c)/2);
}
}
switch($method)
{
case 'ascii':
$char = '';
for($i = strlen($d); $i > 0; $i -= 2)
{
$char .= chr(substr($d,-$i,2));
}
break;
default:
$char = $d;
break;

}
return $char;
}

Usage is as simple as iron("string","ASCII") for ASCII output (recommended only if you hash it with another algorithm after) or iron("string","numeric") for the normal numeric output. Online hasher is here.