Retake, or delete. There is no other way to save a blurred picture, apart from trying to pass it off as ART. Even then, not all blurred shots can be passed off as art....
Sharpening only works when there is edge contrast to work on, ie, the photo has to be sharp in the first place.
I'm sorry, but techonology is not going to help you if your fundementals are not sound. Retake the photo, else curse your own skills for missing the shot on that day.
You may want to try reducing the image size, i.e. interpolate your image down to much smaller dimensions. If the blur (camera shake and/or motion blur) is not that significant, you may be able to get a somewhat usable image at the reduced size. This is similar to "zooming out" in your image viewing program until the picture looks vaguely sharp (or at least you can figure out what the original scene was supposed to be like).