You can also fire relays from one brick to another.
For example, if you do:
onActivate -> Self -> fireRelayWest
and you have another brick west of the first brick, that brick would do any event triggered by a relay (onRelay ->....)
This can be used for numerous things, including "cables" or, combined with delays, detonation wires. You could also use these if you don't want to use named bricks.