My Aunt always has problems with working on her projects as soon as the sun sets, so I thought she could benefit from glow in the dark knitting needles. She has lamps, but they don't seem to put off much light when sitting in her chair. She also likes to knit while camping and lighting is scarce.
This set works on batteries so you can conserve the power when they are in the off position. They are size 10 and come in 13" length. The seller does have several other sizes available, so whatever project you are working on, you should be able to find the right pair for your needs.
I actually thought they were a bit of a gimmick, but when my Aunt tried them out, she said she was able to do her knitting at the campsite this last summer. It was just bright enough to see what she was doing beside the kerosene lamp. She also mentioned that she had been working on dark green socks for her grandson for work and that the lighted needles made it so much easier to see that dark yarn.
Considering there are many places where you need to focus a little light on what you are doing, I can see this set being quite handy!