While learn to solder kits can be entertaining, at the end of the day I’d wager that most become shelfware in fairly short order. On the other hand, this kit from The Curious Electric Company not only serves as a beginner soldering project, but also functions as a solar powered keychain light.
The device includes a small solar cell, which charges an ultra-capacitor when a light source is available. This gives it enough energy to power the red LED for about an hour, or the white LED for 20 minutes. Another cool feature of this device is that if you need a tiny bit of power for something else, the P4 terminals are connected to the ultra-capacitor, opening up all kinds of possibilities.
This little device would be great for your for your quick lighting needs, or even for an emergency situation. For that matter, if you have a need for illumination during a power outage, be sure to check out the Tindie Guide to Emergency Lighting for a few ideas.