OP-AMP Configurations Recall

It has been a while since I last dealed with op-amp. So, it is good to recall some of the most fundamental op-amp configurations, especially when I am dealing with them recently.
In my opinion, op-amp is like logic gates in analog world. You need op-amps to transfer your analog inputs into your desired analog outputs.
The following are some important notes for me, not for you, of course, :)!

Common Names	Op-Amp Circuits	Transfer Functions
Voltage Follower Amplifier		Vout = Vin
Inverting Amplifier		Vout = -(Rf/Rs)Vin
Noninverting Amplifier		Vout = (1+R2/R1)Vin
Difference Amplifier		If R1/R2 = R3/R4, Vout = (Vin+ - Vin-)(R2/R1) + Vshift
Summing Amplifier		Vout = (R2/R1)* (V1+V2-V3-V4)