here's a link to a garden apron from Martha's website. This is the only photo of it-which doesn't look very apron-ish, but it is for an apron, I promise. The dishtowel apron is super cute, also from Martha's site and that pattern is here.
Kay sent me this great link to a free pattern for a knitted apron from Knitty. Thanks! And here is the free crocheted apron pattern that was in County Living Magazine last month. And another crocheted apron, this one is for gardening, here. Here is a pattern for a child's bonnet that turns into an apron. (boy, I need to come up with a better word than "here", will work on this, I swear.)