I know about fretlight - they did a fair bit of advertising in the UK a few years back.
I'm divided on the wisdom of them. On the one hand, all the scales / chords etc are lit up for you so you can learn the patterns, but that brings me to the negative. All it can teach you is the patterns, it won't give you any understanding of anything beyond that.
Through repetition you'd learn the scales with it, but being as the information is widely available on the internet / books etc you'd probably be better off buying a cheaper guitar and using some of the money you save to buy books, maybe take a lesson a month to stay on track / pay for a guitartricks subscription (which I don't have, but it helps alot of people) and whatever else.
Once you get started you'll find that you could spend any amount of time and money on guitar stuff... :D
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