Getting eth0 to come up automatically when plugging in the cable

[Micha <michf@post.tau.ac.il>]

Is there a (not too complicated) way  to get eth0 to come up automatically
(with dhcp) when the cable is plugged in and go down when it is disconnected?

I currently have the default setup where it is defined as auto with dhcp,
so dhcp is always running, 
/etc/network/interfaces:

# The primary network interface
allow-hotplug eth0
iface eth0 inet dhcp
auto eth0

I also see a message in dmesg that says that it
recognises that the cable was connected and disconected

i.e on disconnecting and reconnecting the cable I get
e1000: eth0: e1000_watchdog: NIC Link is Down
e1000: eth0: e1000_watchdog: NIC Link is Up 100 Mbps Full Duplex, Flow Control: RX
e1000: eth0: e1000_watchdog: 10/100 speed: disabling TSO

Taking out the cable leaves the interface up though and reconnecting it doesn't
reacquire a network address.

Is there a way to do that automatically?

Thanks