A simple oscillator using a 74HC14 CMOS inverter makes a excellent driver to flash leds. Put them in a jar and place it in your window for a showy display.
Step 1: Make the Circuit
Run four vertical bus wires of bare #18 wire between the top lid and bottom disc in the jar. I used a thin phenolic material to support the bus wires. One disc to replace the top lid of a Ball canning jar and one on the bottom for support. You could use perf board material that has copper pads.
One of the wires is used for the positive bus and the other three are negative. I start by spreading out the positive (pin14) and negative (pin7) of the ICs. Solder and support the ICs to the bus wires.
Step 2: Schematic
This is the schematic of one of the IC circuits. I was able to fit 4 ICs along the bus wires. Just tack solder all the parts to the IC legs and build up your circuit. If you use a water soluble organic core solder like Kester 66, you can wash off the flux residue when done.
The values for the resistors and capacitor are not critical. Now is the time to get rid of those extra mix of resistors and capacitors just laying around you shop.
You can download a pdf of the schematic at my Jar-O-Circuits page.