Oh this thread is great! Spudrick that is so cool. I have seen a couple of people use led's like this - great idea.
I mananged to print my circles out on several A4 sheets ... bit floppy so i tracked down a printers that did it in one piece: even tho it was 52x52 cm he initially printed it out 58cm! (My print was much better quality too tho

). I have since realised a slight problem in that I have got into the habit of moving my base around a fair bit whilst viewing (due to being on a balcony I have to get in close to the railings to go high and go back from the railings to go low), which will mean realigning frequently. So I may have to go the metal strip + indicator way. Plus I definitely need a bubble level for the base. (Goody, a trip to a hardware store !!!!!)