I love space saving designs, and am also a big fan of how to make the most of tiny spaces... Japanese design is especially good at this type of thing; you can also get lots of good ideas from looking at how boats are designed.

When I moved from Texas to Washington state 11 years ago, it was actually in a school bus converted to motorhome... and again, efficiency of space was an absolute must. Lots of things with dual purpose-- a bench opens and becomes a bed; kitchen counter swivels 90% and becomes dining table, and so forth.

Like the designs in the videos, too... especially the second video, where the "parts" are self-contained within the piece.