Spelling

So the six year old has been progressing on the learning to read thing which makes me happy.  On the one hand, it means we can move on to longer and much more interesting books which is a good thing, on the other hand he has developed this terrible habit of asking how to spell everything and what everything says by spelling.  For instance, we are driving down the street, I know how to spell pizza.  P-I-Z-Z-A  I know what B-E-S-T B-U-Y spells, Best Buy.  What does S-T-R-A-U-S-S- spell?  What does F-U-R-N-I-T-U-R-E spell?  He also does it for commercials and the news programs.  Considering that most of the news broadcast had a ticker at the bottom with the headlines, this is a constant running commentary.  Frankly, it is annoying.  The only question is how to get him over this stage and into the reading quietly to yourself stage.