After reading an article on www.instructables.com I just had to use up some of my parts to make this one.  Aside from my sub standard rush soldering job, this is still pretty cool.  I know, I know, "you're not supposed to solder to a lithium battery, IT IS VERY DANGEROUS." You can, however, cold weld them!  Experiment on your own but NEVER EVER pass the current of a cold weld machine through the coin cell.  I plan on making a few more using different size batteries, LED's and various connection techniques such as no soldering required.  I may make several of these using cr1025 lithium coin cells and white LED's for my wedding reception.  Give it that star field appearance/feel. I would want them to be easy to make and store in the "off" mode and easy to turn on.  The drawing below may hint to what I will try with heat shrink tubing.

This is my first attempt at making a lighting-bug using solder free construction.  The end product is quite encouraging.  The one pictured doesn't operate. I heated-up the coin cell too much while shrinking the tubing.  The entire device (minus lead) is less then 3 cm long.  The CR1025 battery is 1 cm by itself.

• CR1025 "Lithium" Coin Cell
• LED - White
• Heat-Shrink Tubing: 5/8 x 5/8 and 1/8 x 5/8
• Slice of plastic straw

Assembly:

Shrink the 1/8 X 5/8 piece of tubing around the cell.  Bend LED leads so they are ensured to make contact with the cell.  Insert cell.  Insert assembly into large piece of shrink tubing.  Shrink, CAREFULLY!

Here is a couple I made today.  it took me less than 10 minutes to make both.  Making them in large quantity would not be difficult.  The hardest part is shrinking the tube around the cell.  

Practical Application:

• earrings
• thumb tacks
• disposable, temporary, task lighting