This is driving me nuts too And with no cabinet to store all our collectibles, I'm really cranky with it.
MODIFIED: October 8, 2014 12:15 AM:
I investigated these matters further, and it looks like I made a few mistakes. Sorry about that! I modified it below to make it correct.
_Annika_, I am hoping for cabinets to come soon, too!
For now, here are some alternative storing options in the absence of cabinets:
Fruits and vegetables can be stored in the refrigerator, but not the flowers nor any fish.
Postcards can be stored "on" the bulletin board on a wall. These have the "inspiring" mood effect if you choose to enable it. Plus, each and every one of the 14 postcards (Inspiring Decor: 3) can be enabled for a total "Inspiring Decor" score of 42 from something the size of a medium painting!
Elements can be stored in the Elemental Display Rack, which I think is pretty cool. The elements have the "focusing" mood effect if you choose to enable it. Plus, as above with the postcards, each and every one of the 15 elements (Focusing Decor: 3) can be enabled for a total Focusing Decor score of 45 from something the size of a small chair!
And, of course, Microscope and Space Prints can be placed on the walls. There can also be enabled as Focusing Decor. Each microscope and space print, regardless of size or rarity, have Focusing Decor: 2.
Smaller crystals and smaller metals (and fruits and vegetables if you want them on display...) can be placed on shelves on the wall and also on the bottom shelf of the "Bold Statements Console Table." I really like this feature! However, similar to the allowed refrigerator contents, flowers can't be placed on shelves, which is kind of odd in my opinion.
Larger crystals, frogs, MySims trophies, metals, aliens, and fossils can only be placed on cabinets, dressers, or tables. The benefit of doing this, though, is that some of these can be used to influence your sims mood by clicking on them in live mode and "enabling" each of their emotional auras.
MySims trophies - Playful Decor:
Large Crystals - Energizing Decor: 2
Small Crystals - Energizing Decor: 3
Aliens - Confident Decor ** Note: In LIVE mode, only some of the aliens give the "Enable Emotional Aura" option. In BUILD mode, some say "Confident Decor: 3" when you pick them up; however, in live mode, you cannot enable this aura. I assume that this is a bug that will be fixed. I guess there is a small chance that the emotional aura of these objects is simply always on, but that would be inconsistent with the rest of the game objects.
Metals, small and large - Some type of Decor: UNKNOWN # **Note: When you select the metals in build mode, they are just labeled "Environment: 2," but in live mode, you can click on them and Enable Emotional Aura. My sims tend to become focused around them, but that could also be due to many other actions or items. I will try to look into it.
No Mood Effect: Frogs and Fossils
Fish can be mounted and placed on the wall, but, of course, that doesn't allow you to use them as bait later. Mounted fish on the wall do not have any emotional effect.
On one hand, by NOT giving us cabinets, we are forced to discover the benefits of keeping these items "out in the open." It could also be a way to discourage us "hoarders" from collecting thousands of items (as I have done many times), which seems to inevitably slow down and crash the game. But who knows?