Sending money internationally. Comparing products across brands (they all have specs but the way they sort the specs is different and it's a pain to flip through tons of tabs). Finding a chair to fit my kitchen table (given the dimensions of both). Diagramming my bedroom to try to figure out if I can build a better bed. Finding furniture that fits in a given volume (in my case, I want to find a trolley or counter tha…
On point 3, have you tried Autodesk Homestyler? I used it for a similar purpose :)