It's pretty clear that most people have a hollywood sense of what a mutation is. Giant ants, Green skin, etc.
The genetic code is rigged so that many point mutations are synonyms.
Not to mention (as you already have) that any point mutation is most likely to occur in a non-coding region.
For the lurkers: The majority of the genome is non-coding, a small portion of which comprises highly-conserved non-coding areas which appear to be control sequences. The rest is comprised of sequences which code for proteins. There is roughly a 1/3 chance in the coding and control regions that it will hit the third nucleotide in a codon leaving the amino acid pretty much unchanged.
What is more interesting for evolution outside the possibility of having one of the above point mutations becoming part of a coding sequence are those sequences where an active portion of a gene is affected but the resulting feature/function is invisible to the selection of the time. What is a neutral feature under current selection can become either beneficial or detrimental under differing selection.