Archaeology is about stuff--things past people made and used. The structures and things we create are part of us, and who we are: the archaeologist Brian Schiffer has insightfully defined a human being as, in material terms, a particular kind of primate compounded with artefacts. Making and doing are integral to people and their relationships, as David Gauntlett has argued. Richard Sennett has written on the under-appreciated social importance of skills ('craftsmanship'), from carpentry to musicianship. We get great satisfaction from undertaking projects of many kinds, including, in my case, creating images--and making models.
In recent years, with my son Tom, I rediscovered the pleasures of building things in Lego, first through helping him assemble Lego sets, then through building custom-designed things which he requested (MOCs. i.e. 'My Own Creations'): mostly tractors, construction machines, and Star Wars vehicles. When he moved on to an interest in real cars, I found this so much fun that I started building things for my own amusement, as a form of relaxation; I have turned into an AFOL (Adult Fan Of Lego).
Lego is an ideal problem-solving medium if you like to think in 3D. Trying to create particular shapes using the wide yet finite range of components available is endlessly absorbing. Flickr is home to images of thousands of amazing Lego creations. I think of it as 'Legoku': puzzle solving, combined with elements of sculpting, design and engineering, plus the added attraction of retail therapy--not so much through buying Lego sets, as procuring specific parts from the many small Lego dealers around the world who sell though Bricklink. It's not the cheapest hobby, but probably better than spending the money on beer and baccy...
Perhaps inevitably, most of my MOCs are military themes.