I found a nice set of Logic gate circuits on instructables. I decided to build a basic AND gate as per the circuit here.
I decided to download and put the diagram here so ALL CREDIT goes to the instructables website.
I took a photo of the working circuit.
As this is a digital logic circuit the truth table is as follows.
2x 10k resistor
2x 2n2222A transistor
Blue LED (you can use any colour)
2x Button Switches
Update from 18/8/2015
I have now soldered this up.
And soldered side for completeness
This took about 1/2 hour to solder up, I had prepared before hand and laid out most of the components on the board pushing the legs through.
If you want to learn more about logic gates Matthew Lugg has started an excellent series on the Tech jam website on this, focusing on how to build gates in Minecraft with redstone and moving on to produce adders, and memory circuits.