My son started looking at web design software last year when he was 5 and taught himself how to use it, he had his website online when he was 5 yrs and 9 months old. He updates it all the time and tries out new ideas on it (some of which work and some don't) but for a child who's had no formal teaching at all I think he's done OK.

I'd be interested to know if this 8 year old still holds the record...if so I'd say my son has beaten it!