Sentence fragments, shunned by rigid writers and grousing grammarians, often mimic speech and thus pick up the pace of your writing. Unexpected, they can command attention to strong points and comments. Here's an example from a recent New York Times article on revitalizing Starbucks:

But revitalizing the Starbucks experience is not going to be enough. Not even close.

The full sentence would have been:

But revitalizing the Starbucks experience is not going to be enough. It will not even be close.

Stripping the subject and verb from the front and leaving the fragment drives the reader straight to the point.

Here's another example from the ClearWriter archives:

The marriage of America and the rest of the world is just that. A marriage, for better or worse.

The more conventional version might have been:

The marriage of America and the rest of the world is just that, a marriage for better or worse.

A small difference, but a difference. Because the fragment is unconventional, it draws more attention to the point than the conventional version does. Just be sure that the passage merits the attention.