I had a bunch of EL wire left over from another project, and I wasn't really sure what to do with it. So I thought to myself, hey, cram it all in a jar! So that's what I did. I soldered all of my EL wire into one strand, made a power backpack that powers an EL wire driver from a pair of 9V batteries, and wrapped the strand around the inside of the jar.

Step 1: Parts

The parts you'll need are:
EL wire (I only used blue and white because that's what I had on hand, if I was building this from scratch I probably would use a bunc of different colors) (A good source for high-end wire is elwirepros.com, but eBay has some fairly good lengths of EL wire with free drivers super cheaply)
EL wire driver (make sure it's rated for the length of the strand)
Two 9V batteries
Pushbutton
Glass jar
12V voltage regulator
Assorted soldering supplies, wire, heat-shrink tubing, etc.

Step 2: Making a Single EL Wire Strand

My final design needed a single strand of EL wire, so I soldered together all of the shorter strands. EL wire is a tricky kind of wire to solder together end-to-end, but I developed a pretty good way to solder it together. For starters, it's important to know the anatomy of EL wire. EL wire has a central core of solid wire coated in a special phosphor. This core has two thin conductors spirally wrapped around it. This assembly is then surrounded by a plastic sheath. By applying an electric AC potential across the central conductor and the surrounding conductors, the phosphor glows. This anatomy makes soldering the wire together kinda tricky. I show some pictures below that outline this process. First, you strip off the plastic sheath while being careful not to break the two thin conductors around the phosphor. Next, bend the thin conductors away and strip off some of the phosphor (I usually scrape it off with some wire strippers and a utility knife). Thirdly, solder the two central conductors together. To link the two thin conductors, solder on a piece of wire to the thin conductors on each wire. Finally, use some heat-shrink tubing to hold this assembly together. Using clear heat-shrink tubing would make the links less obvious and let more light out, but I only had some black heat-shrink tubing on hand.

Step 3: Power Supply Backpack

The power supply backpack I made is fairly simple. It has two 9V batteries wired in series to provide an 18V supply. This is then passed through a 12V voltage regulator to supply 12V to the EL wire driver module, which is in turn connected to the EL wire. I used a pushbutton mounted to the top of the jar to turn the lamp on and off. I have a few pictures covering this power supply below. To mound the power supply, I glued the backpack onto the back of the jar. I originally had the power supply in the center of the jar, but it didn't look as cool.

Step 4: Inserting EL Wire

I pretty much just wrapped the long strand (about 40' long) around a water bottle to get a loose spiral, crammed it into the jar, and arranged it a bit to look as cool as possible.

Step 5: Done!

I made this using bits I had left over from another project, but if I was building one from scratch, I would use some different colors to coordinate it a bit better. I'm actually considering making another one as a present that uses every color of EL wire you can buy. I'm still proud of how it came out though, it's a lot better than having a pile of bits sitting in a box somewhere in my garage.