Midwestern reader Bodie has written:
You should do a post on the correct use of the semicolon. It's my favorite punctuation mark that folks abuse.
The semicolon is an often-misused punctuation mark; most Americans are stymied by its usage because it requires them to remember things like "independent clauses," not things like "where Justin Bieber celebrated his 19th birthday" (news story courtesy of supposedly-serious news agency ABC News).
Some folks go so far as to call for a new punctuation mark that absolves the user of such concerns. (Four of those eight seem like legitimate improvements in my eyes.)
Semicolons connect two independent clauses with a common theme; if both sides of the sentence can stand as complete sentences in their own right, yet the second seems like an elaboration on the first, a semi-colon is appropriate. If the second portion of the sentence CANNOT function as an independent clause, the semi-colon is not the punctuation mark you're looking for.