I found my favorite D.I.Y. wine bottle project on Bellalimento.com. All you'll need are a few wine bottles, some chalkboard paint, and a few inexpensive daisies for an awesome vintage look. I also love the idea of roses in these.
To show guests the table number you can group bottles together, corking one and placing a small card on top. And if you're using chalkboard paint, you can easily write the table number and guests directly onto the bottle.
If you're having your reception or service in the evening, you can create an ethereal look with L.E.D. string lights inside wine bottles and you can find a great D.I.Y. article on eHow.
And if you're looking for something a little more colorful RuffledBlog has an article on how to create incredible pop art, bright wine bottle centerpieces that look fabulous with a few Gerber daisies.
*Image Credits, Left to Right, Top to Bottom; Chalkboard Wine Bottles via Bellalimento.com, Pop Art Wine Bottle Centerpieces via RuffledBlog