From: WestOf Moonwall
Is there any way to get a list of the current locations of all objects owned by a resident
Unfortunately, no, but here are some tips:
From: WestOf Moonwall
Walking so far away that it is no longer visible while building.
Obvious answers:
1. Don't do that.

2. Retrace your steps.
More technical answers:
1. Increase your draw distance.
2. Disable camera constraints, so you can move your camera as far as you want. (Advanced -> Disable Camera Constraints) Ctrl-Alt-D will bring up the Advanced menu.
3. Disable Limit Select Distance, so you can keep objects selected, even if they're far away. (Advanced -> uncheck Limit Select Distance)
From: WestOf Moonwall
Accidentally burying it while building.
With camera constraints disabled, you can move the camera underground. Also, you can make the ground invisible by disabling surface patch rendering. (Advanced -> Rendering -> Types -> uncheck Surface Patch)
Make it a point to get VERY good at controlling the camera. Don't use the on-screen controls; they're extremely clunky and underpowered. Really, they're beyond awful. Instead, use the alt-mouse controls. If you need help learning how to use alt-mouse, here's an instructional diagram:

From: WestOf Moonwall
Executing a script that makes it go somewhere else.
If you were writing the script, you should be able to find the object quite easily. Just open up the script and take a look at the numbers.
If you inadvertently dropped a script you can't read into the object, that makes things more complicated, of course. In that case, you MIGHT be able to find it using a scripted scanning device, if you've got a rough idea of where it is. Don't ask me for the specific how-to's on that, though, since I'm not a scripter.
Beyond that, all you can do is wait for a landowner to return your stuff to you fr0m wherever it ended up.