I had recently explored the right side of the fork that's on the right, and it was boring, so I went left. Dark, going down, sppooooky. And look, Chicky followed me pretty darn far for a random movement! It Loves me! Or knows a chicken is a snack to most things. . .
Exploring farther in, I find yet another ravine, this one not really a ravine as it fully underground. Skipping it magma goodness in favor of a magma lake, I dig arounf it, craving a path through the bleak grey stone. Nope, no
blue metal diamond. A dead end though. I stop to smelt some more iron and craft a bow/picks.
Don't fall in!
Also, one thing I never worked out about Minecraft - if you drop items (like the wooden sword or the slime balls in your screenshot there), do they just remain there forever more? Or do dropped items vanish after a certain amount of time/when the chunk unloads/etc?
I tend to build dozens of chests to store lots of random crap in case I ever need it again. It would be handy to know I could just chuck it all in a corner and it'll stay there until I decide I need it.
Ahh, Well, from when I read the wiki it was 5 minutes. Was awhile ago, though, so maybe it changed. I know if the chunk unloads the whole things goes into stasis, including the items.
EDIT: As for chests, I usually do. In fact I typically make a 'starter' base outside the shaft (or just inside) complete with a bed if its reasonable far from home. I run topside, drop off a full load of ores/rocks, and go back down, often getting 3 double chest's worth of loot before transporting home. That's, of course, if I don't have enderchest.