Yea thats a good system... might have to make a funny one like that for random #s lol
I use an app called "WhoIsIt" ... it will let you set a different ringtone and vibrate pattern for everyone in your contact list if you want. It also lets you set VIP's in your contact list, and VIP's will ring at regular volume even if the phone is in silent mode or on vibrate. It's good since my dad is elderly and not doing well, that way if one of my family members calls it will ring no matter what. It's a great app.
The ringtone that says "An idiot is attempting to reach you on your cellular device" I got from Zedge, along with 250 wallpapers. My wallpaper changes automatically every 15 minutes.