Was reminded a few days ago at dusk...Driving along a semi-rural road, I saw a cyclist, all in black about 20' away (7m). a few seconds later I saw a jogger, with just tiny bits of reflective tape about 200' away (70m). Ten times the visibility distance.

Reflective tape, patches, shoes -- anything --will help you get found. Its cheap and easy to add to your pack, gear and clothing.
(Stick-on or sew on.) Especially important for those travling on/ by the roads and for children.

teacher

Well stick them everywhere, including most of mine gear. Makes it much easier to find your stuff back in the dark.

When running or cycling in the dark i also have LED's lights, to make my self more visible.

Please note that there is a huge difference between "reflective" and "retro-reflective." You are really discussing retro-reflective, NOT reflective.

http://en.wikipedia.org/wiki/Retroreflector

When i used to bike to the university every day, i put silver retro-reflective tape on the inside of the wheels where the spokes are for about 1/3 the circumference. This made it very visible because of the motion and was useful even when broadside because the wheels have a curved profile. I also had tape on the outside of the cranks and on the helmet. Best part was all of this tape was nearly weightless and disappeared during the daytime.

Cheapie reflectors, superglue, velcro strapping. It might not be pretty, but it works and it lets you put a reflector anywhere.

In the constant search for high quality retro-reflective tape and having tested various tapes on dog harnesses, collars, rough totes, bikes, etc, for years now, so far for me the Reflexite brand tape works the best. Its extremely bright, takes a lot of abuse, and isn't a PITA to remove. I usually replace it about once a year under heavy use. The 3M Solas tape works extremely well but doesn't stand much abuse, and is very difficult to remove. IMO its amazing tape but most suited for use on flexible materials and/or areas that aren't exposed to abrasion. Or I guess you could just keep reapplying it every 4 months or so. From my experience, thats about the time it takes for the outer coating to wear off and the reflective quality of the tape starts to degrade. Thats under moderate to heavy use. But then again, I'm pretty rough on my gear so YMMV.



here's the Reflexite

http://www.identi-tape.com/hi-intensity.htm



here's the 3M Solas

http://www.identi-tape.com/solas.html

I have been using Glo-Flex tape for years with good results. It is a combination of retroreflectivity and photo luminescence. I have it on some clothing and a lot of my gear.
At $13 for a five foot roll it is not cheap but I like it. You can find it at Galls.com.