First step: Buy a globe and cut in in half using (for example) the beloved Dremel. Sorry for the product placement, but I guess whenever it's deserved it all right...
The equator serves as a great cutting line :)
There is some nasty smoke coming from the glass fiber, I recommend a well ventilated area.
Next step was to drill holes wherever I've been. I chose to go with 3mm LEDs and that also set my drill bit size.
I realized that Europe is small, I had lots of holes close to each other and originally I thought that I could put a LED in every city but in some places I had to settle with one hole in every country.
The picture below is the inside of Europe. The holes were perfect for just press fitting the LEDs, but I eventually put some hot glue there anyway.
After Getting all the LEDs in place I soldered on bare thick copper wire recycled from a huge 380V 3-phase cable.
For simplicity and to be able to quickly add new destinations (LEDs) I chose to put all the LEDs in the northern hemisphere in parallel and same for the southern. Then they are current limited with a single resistor and run off a 12V battery.
Now first I wanted to have a slipring to be able to spin the globe and still have lights. Instead I chose a battery and the little contraption above. The top part is connected to the roof and the bottom part holds a bearing so that the globe can spin. The kog is just for locking the bar in place.
Also here is a little montage I made for Instagram of the build process: