Kelly and others,
As one of the fellows of the Society of Antiquaries of Scotland, I will interject that there are very few people in the world with a family crest ( much less than 1%). The crests you look up in books, get on coffee mugs, and buy in souvenir shops printed on ties belong to those few people. A crest is granted by an authority, most are from the Lord Lyon of the Lyon court in England, but there are other registries. The ones you get offered in the mail are either made up or belong to people who have the same last name as you do. Unless you are the direct heir of that person, you should not use that crest.
In the UK, it is actually a legal issue, but just like Jay-walking , or wearing a fake Rolex, it is not enforced anymore.
The process of being authorized a family crest is expensive and takes several years.
Just as you would feel a bit ripped off if someone started calling themselves hellgap, or marking their knives "Weins Knives", the people who rightfully bear arms ( different from the second amendment) frown on others taking what is rightfully theirs.
Stacy Elliott Apelt, FSA,Scot