American currency has fluorescent ink.
Dissolve aspirin in water and it flouresces.
I have several of the keychain lights from PhotonLight.com. They have a 370nm UV light listed.
No affiliation, of course. I just like 'em.
You missed out. A little over a year ago, I bought fifty 375 nm discrete LEDs from some guy on eBay, and offered up some of them here to the first few people who responded. I still have a few left. Sorry, they’re mine 
The scorpion suggestion is legit, I’ve seen it, a fascinating sight to behold
Sorry, I could not resist.
Hmmm, I have menthol in my cigarettes. I wonder how that would go over.
I found mine at Amazon.com by searching for “LED keychain.” I bought a Photon Micro-Light II (purple). About sixteen bucks, if I recall. The package says it’s 405nm, and it’s no damn good at all for finding your car keys or for illuminating your dark house if the power goes out — even in complete darkness it’s just a faint purple glow barely visible on a wall at ten feet. If you’re looking for a light that’s useful for finding your way around in a dark place, get blue, green, or turquoise.
That company also makes the Photon Freedom Micro Light in an actual, honest-to-gosh UV spectrum. I can’t find those specs online, but it’s about $30.00 through Amazon.
Not affiliated with the company; just reporting where I got mine.
Back to report that Sugar Frosted Corn Flakes and Cap’n Crunch both faintly fluoresce to the particular black light I have. Also the F on the cover of Life cereal.
If you, like me, are the sort of person who has a lot of marbles, then you should check them out. Some marbles are made with uranium glass, which turns a lovely yellowish green. In regular light uranium glass is has a slight yellowish tint to it. Some old glasswear is made out of it, too, and it’s sometimes called vaseline glass.
I like to go into my younger brother’s room with a blacklight, because he has a lot of little plastic things that glow nicely.
Visa/Master and other credit/debit cards.
Your Passport (mine has hidden page numbers and other cool markings).
I’ll third the scorpians. It’s the big hit at presentations. I always take along an 14" blacklight in a portable unit and glow up our big African Emporer. Gets a big gasp every time. He turns a bright bluish green.
You might want to check your rock collection, too. Some pretty common ones like calcite fluoresce. You can order samples of uv-reactive rocks from rock companies like rocksandminerals.com . Some of the coolest ones need a short-wave light, unfortunately.
It’s a popular pastime with the newbies over here as well. We take a large UV light that runs off a car battery. After dark you can usually find a LOT of scorpions hunting dinner in the desert. Fun, but it makes sleeping later a bit uncomfortable. :eek:
Regards
Testy
Are there any hypotheses about why scorpions fluouor… flouuo…
glow?
Fish and I are in the Pacific Northwest. If we see any scorpions here, there’s likely to be a bigger problem at hand. Like “the walls of the fifty-third precinct are bleeding” type of a problem. So we probably won’t be walking around with a UV light. Just FYI. 
Red Bull Energy drink, I have seen night clubs use it in drinks and the lights in the club make them glow a lovely greenish yellow.
Great idea for parties IMHO.
Glows light green? Probably calcium-based minerals. Teeth also glow light green (and you can easily detect the presence of fillings and crowns.)
Here’s one: get a fluorescent yellow hi-lighter (magic marker) and draw on your skin. This fluoresces brightly (so draw bones!) But also it’s easily visible in norma light. So wash it off a few hours later. By then some of the dye will have soaked into your skin. The remaining dye is invisible under bright light, but you can still see it under UV illumination.
PS are hi-lighter markers toxic when used to draw a human skeleton all over your hands and arms? I’m not sure, but the dye color looks like fluorescein, which isn’t toxic in those amounts.
Anything with “Day Glo” colors or other fluorescent colors (Day Glo is a copyrighted name). They look bright in daylight, but they BLAZE in the dark under UV.
White clothes, especially after being washed with a “bleach” that has “brighteners”. The “bleach” itself, too. (Tide, Bold, etc.Look for fluorescent boxes)
Coca Cola glows a disgusting greenish color
You can buy paints, dyes, and inks that are invisible in ordinary light, but which light up incredibly uunder UV. (My daughter has a pen she got at the Spy Museum in Wasgington DC that has such “invisible ink” in the pen, and an attached UV LED to make it visible)
Transparent Plastic with bright color dyes in them can really light up. Plexiglas with laser dye in it is awesome, if you can find it.
Sodium Salicylate will glow with a uniform bluish-white under UV illumination of just about any wavelength.
1960s-style “blacklight” poster. Go raid Spencer’s gifts, or your local equivalent (Newbury Comics in the Boston area has lots of posters)
Fluorescent minerals. Fluorite, surprisingly, is pretty lame, but things like Willemite are very impressive.
It’s really good for charging glow-in-the-dark Silly Putty.
Yeah, take it into a hotel room and prepare to be disgusted.