Doh, I was supposed to add a poll to this, but I forgot.
Do you take it to the standard 3rd Boyce-Cobb Normal Form? Or go all the way?!
Personally, I try and take it all the way to Domain-Key if I can during the logical design phase, but generally it denormalizes to the 3rd Normal Form when it actually comes down to planning and building the actual schema.
It does take a little longer, but I like doing it, and it help me keep on top of everything as I go into developing the ASP. Also helps keep on top of those rules!!!
D is right, you should normalise all your data to the third form. It is difficult at first but gets easier with practice. Not only is it professional to normalise, but it really saves a lot of hassle later as a lot of problems can arise it the normalisation stages are not followed. If you don't know anything about it read a book. I reccomend
Database Systems by John Jones