ping the machine, and then dump your arp cache with "arp".

eg

Code:
simon@lappy:~$ ping BelkinPrintServer.scottlan
PING BelkinPrintServer.scottlan (192.168.1.13) 56(84) bytes of data.
64 bytes from BelkinPrintServer.scottlan (192.168.1.13): icmp_req=1 ttl=64 time=8.86 ms
64 bytes from BelkinPrintServer.scottlan (192.168.1.13): icmp_req=2 ttl=64 time=9.74 ms
^C
--- BelkinPrintServer.scottlan
...