!idle on

var p = getUserbase().properties()

p.set("anti-idle", true)
send("Starting Anti-Idle")

while (p.get("anti-idle"))
{
	talk("anti-idle message")
	sleep(600000)
}

!idle off

var p = getUserbase().properties()
send("Ending anti-idle")
p.delete("anti-idle")

(the code here differs slightly from the downloadable version)