I am in love with the chalkboard trend for weddings.
They're cute, customizable and I think they're becoming increasingly easy to find. Save-On-Crafts has a bunch but beware their shipping charge... yikes!
I went the DIY route on this because I can't justify paying more for shipping than the total of my supplies!
What I started with:
1 Foam Brush
2 Rustic 5x7 picture frames (with a hanger on the back)
A hot glue gun w/ glue sticks
1 (4) yard spool of non-wired ribbon in a width >1/4"
Paper to protect your work surface
Prep your frames by removing the cardboard inserts(don't throw them away!) and the glass carefully. I removed the easel-back but it was stupid-hard. If you leave it on, you can use the frame after the wedding possibly.