Ubuntu Networking :: Create A Script So That The Mac Address Get Changed At The Boot

I'm trying to create an script so that the mac address get changed at the boot for every interface in the computer (eth0, wlan0, etc...).

I've tried with

Code:
for IFACE in $(ifconfig -a -s | egrep -v "^(lo|Iface)" | cut -f 1 -d" ")
do
macchanger -r $IFACE
done
and with

[Code]....

It would also be nice if there was a little program which would ask you at the boot if you want to change the mac address.