Not certain if you're running into the same problem I had when trying to generate an ARP table since the devices I'm trying to query don't have the BridgeMIB extensions on them... Just in case it is, try doing this:

	$textMAC = unpack( "H*", $binMAC );

where $binMAC is what the SNMP get gives you and $textMAC is the MAC address in string format.

In your code, you might do:

print "$key -> " . unpack( "H*", $macTable{$key}) . "\n";

I also prefer the Cisco style presentation for the MAC addresses rather than the dashed approach, so, if you like the xxxx.xxxx.xxxx output, you can also do this:

	$macaddr = substr( $macTable{$key}, 0, 4 ) . "." . 
		substr( $macTable{$key}, 4, 4 ) .  "." . 
		substr( $macTable{$key}, 8, 4 );

My reasoning is that the snmpget you specified at the very end returns Hex-STRING but the text looks ok. The trick behind it is that the snmpget program is doing the conversion and presenting a text string, not the raw data returned from the get.