These are a couple of the "Hall" crests I have encountered. According to my reading, a family's "arms" or crest were developed for that family only, so "my" Hall's probably did not have their own crest.
Here are four descriptions of the Hall name. It is one of the world's most common surnames; there are English, Scottish, French and German derivations of the name.
A general description of the Hall name derivation
A description of the English derivation
A description of the Scottish derivation