Strange things scientists carry with them

In response to my post about the biologist carrying a seal head onto a plane, Qov (who writes bo logh, a blog in Klingon) suggested starting a topic on strange things scientists carry with them. I think it's a great idea, so here goes.

I'll start with the items Qov included in her comments:

"A researcher came to visit my supervisor and was stopped at the airport X-ray machine for having what appeared to be a severed human foot in her hand luggage.

She did have the bones of a human foot in her luggage, encased in a plastic that had similar x-ray characteristics as human flesh. She was working on technology to improve x-ray plates, and the foot was her test pattern.

I know another chemist who got in trouble for carrying a cobolt sample on public transport."

I've carried my fair share of strange items around with me; here's a few that I can think of off the top of my head:

• Fishing poles in the desert: As an undergraduate I worked on lizards, specifically Sceloporus occidentalis, the western fence lizard. We caught these lizards in the wild, and the easiest way to do this was to tie a small noose onto the end of a fishing pole, and then slowly wander around the desert (or other natural area) with said pole looking for lizards. Once a lizard was spotted we attempted to slowly lower the noose over its head to capture it, using the fishing pole to allow us to stand as far back as we could. I'm certain we looked ridiculous wandering around on swelteringly hot days with fishing poles and no lakes or streams in sight.
  
  
• Pieces of dead cacti: While working in a lab studying desert Drosophila species, my labmates and I drove around the desert looking for dead and rotting cacti. Once found, we collected pieces of the cacti (with appropriate permits) and brought them back to the lab to use in food for the flies. I even carried bags full of this rotten cactus across the border to our field site in Mexico.
  
  
• Fly rearing equipment: When going on the above-mentioned trip to Mexico for some desert Drosophila field work we brought our fly rearing equipment with us, including hundreds of small vials partially filled with a tan-colored agar-based fly food. The Mexican border agent discovered these vials and gave us a hard time over them; he seemed relatively certain that they were used for manufacturing drugs, and wouldn't accept our explanation that we were rearing flies in them for scientific purposes (sometimes the truth just isn't a good cover story). He held us up for quite a while and made many allusions to wanting bribe money, but we were eventually allowed to go on our way freely. My advisor reported eating the fly food in the past to prove that it wasn't illicit, though she didn't have to do that this time.
  
  
• Datura (Jimsonweed, Angel's Trumpet, etc.): The caterpillars I worked on as a graduate student grew native in the area on Datura wrightii, and thus on many occasions I harvested Datura either from the wild or a batch we had planted at a local field station. While returning from a conference in California one time I made a point of stopping along the highway at every plant I saw to check for caterpillars and collect leaves. What's wrong with native plants, you ask? Well, Datura happens to be an extremely toxic member of Solanaceae (a family of plants containing tobacco, tomato, eggplant, potatoes, and many more) that some people have used as a hallucinogen (see this DOJ report). Thus, you can imagine my concern that a police officer might come along and suspect I was collecting the leaves for my own use rather than as caterpillar food. Note: if anyone doubts the toxicity of Datura, one of my undergraduate assistants, while trimming some leaves, got a tiny drop of sap in one of her eyes. Both of her eyes remained dilated for three days.
  

So, my dear scientific readers, what odd things have you carried around for scientific purposes?

[Updated to correct the gender of Qov, with many thousands of apologies going to her. I should have known better.]