laser pegs anyone?

I'll dig the set out and have a check again, I know at the time I bought it I wasn't particularly well so I didn't really give it the attention it probably deserves. So I'll do that and get back to you with some answers.

However you are aware that Lego themselves actually make some 'light' bricks? These are often included with the limited edition christmas buildings they bring out each year.

There are also some third party light bricks, I remember finding them myself a few years back when I was looking for something similar, although I have to admit I didn't buy any at the time as they seemed quite expensive.

However what I did do was experiment with some of the strip LED's you can buy off eBay etc... Basically they come as a reel of LED's of various types/colours (depends what you buy) which include all the requisite resistors etc... built into the strip. So you just solder a power wire onto the relevant pads and then connect them to a power source (say a 9v battery). The other nice thing is you can literally just cut the strip to the length you want, its all very simple and very effective and to add the final icing the strips are self adhesive

Here's an example of a seller in the UK but you can find many sellers across the world;

LED Strip