So I made a bunch of terrariums today out of a set of unused mason jars (Clearly jam-making was not in the cards this year...or the last...), but was left with a bunch of the lids (the kind with the band that spins on) and nothing to do with them. Since I hate to throw things out, and since I'm crafty, I found a wonderful solution to reusing these little lids. And since I'm taking part in the
Harry Potter Craftalong's Fall Semester, it has become my Arithmancy project (Make something pi-related. Circles? Yes please.)
TURN THEM IN TO LITTLE MINI-FRAMED PIECES OF ART!!

But no, seriously, they look absolutely gorgeous on a wall - just stick a thumb tack or nail in there, and slide the top of one on to it. No hassles, it's pretty much the easiest, cheapest framed art I've ever seen. And they look real nifty, too, don't they?
Want to make your own? Well aren't you lucky. Here's a (slightly poor-photographed) tutorial to how I made them.
Materials:

A two-part mason jar lid (the kind with the flat piece and the band that fits around it)
Scissors
Pencil (optional)
Scrapbooking paper, ephemera, photographs - whatever you want to frame!
Step 1:

Taking the inner ring of the band, draw the circle on to the WRONG side of your paper (or, if you're like me - spaz out, draw it on the right side, and then erase it before you frame it...). You can skip this step if you want, and just cut around the band itself, but I find this is a bit more of an accurate way to measure.
Step 2:

Now cut AROUND the circle you just drew. Be sure to give at least 1/4-inch clearance (or at least the size of banded-piece, if you're using a larger lid), or it will wobble around inside the lid and that won't be nice

But make sure not to make it too big, or you'll have a heck of a time getting it in to the lid later...
Step 3:

Place your now-cut piece of soon-to-be-art paper on top of the flat part of your lid. Sometimes a drop of glue in between the two layers will help keep them together, but make sure you spread it out so you don't get a lump of glue in the middle of your piece. Also make sure there's a semi-equal amount of paper all around the edge (No need to be exact about it, it will all fit nicely in to the lid in the next few steps)
Step 4:

Now bring in the band! Make a sandwich of the three pieces - starting with the band, then your image/paper, and then the bottom of the flat piece of lid.

Kind of looks like a crafty macaron, don't you think?
Step 5:

Here's the fun part. SQUISH! Carefully, but with gusto (don't hesitate, or your paper will go all screwy), push the flat piece of the lid down in to the band. The edges of the paper will fold up nicely in between the two layers - neatening up the piece without any work! If you happen to have edges of paper sticking up over the edge of the band, just give it a trim with your scissors!
Step 6:

Hooray! Give the flat part an extra squish - you can glue around the edge of the band before you squish them if you want a bit of added security, but I find that they stay together very well. Now you can hang them up on your wall, use them as odd coasters, or what have you. THE POSSIBILITIES ARE ENDLESS.

And be warned...they have a habit of multiplying when you're not looking...