The Adafruit 5-pad Capacitive Touch Sensor Breakout is a handy standalone board providing a digital output for each touch sensor which could be used as a replacement for a tact switch, for example. The AT42QT1070 chip handles the triggering and filtering of the capacitive touch sensors so that you don't need a microcontroller. Each touch channel has an LED attached that lights up when its sensor is touched, which is a nice feature when you are debugging your project. The touch pads can be as simple as a piece of copper foil attached to the board by a single wire. The chip operates in standalone mode which means that its I2C is disabled and a number of internal parameters are set to defaults. In particular, pad 0 is configured as a guard channel which means that it gets priority over all the other pads.
Supplied as a fully assembled and tested board plus strips of 0.1in. header pins for you to solder on as required. Adafruit provide a free tutorial to help get you started.
5-channel touch sensor
Per channel LEDs show activity
Channel 0 is a guard channel with priority over the others