However, there is one big fat problem: the sun! When it's dark out, oftentimes the places I'd really like to have a little extra light are just the spots you can't leave a sun jar due to lack of direct exposure to sunlight.
The obvious solution to this dilemma is to separate the solar panel from the sun jar. I extrapolated this a bit further and realized that the only thing you actually need in the jar is the LED, and since you don't have to cram all the other electronics in there, you don't have to stay with the classic sun jar shape.
With this in mind, I combed craigslist for some suitably shaped glass blocks, went to Home Depot for the appropriate solar light, stocked up on speaker wire and came up with the Solar Powered Walkway!
***UPDATE 5/5/10: If you build this project yourself, or something similar, post some pictures and I'll send you a patch!***
If you are the first person to post a picture of your completed light-up walkway to the comments, I've got a 3 month pro membership to instructables that's all yours!