Have you ever wondered how the shoulder bag with mobile pocket came into being? Living in Motion, an exhibition at the City Arts centre in Edinburgh curated from the Vitra Design Museum in Weil am Rhein, Germany, explores the need for flexibility and mobility in our lives, and how these needs are ever expanding as our leisure and working lives merge. The exhibition is arranged in themes such as transporting, combining and adapting. It's not a chronological method but sometimes illustrates how ideas were carried across continents - a Japanese lacquer picnic box and British bakelite picnic case placed together allow the viewer to compare the elegance and functionality of both.

In the assembling and disassembling area, examples include Vera Franke and Frank Steinert's Furniture PlayStation 2000, which allows the basic elements of long covered-foam rolls in steel frames to be moved to create sitting, reclining and work environments; but this looks awkward and amateur next to the sheer simplicity of Alvar Aalta's 5 stools (1932-33) which stack in a beautiful curve of varnished wood to be beautiful and functional. Some ideas look contrived - Nhew PAD - a prototype one-room living space that transports in a crate, is uncomfortable next to the yurt, employed by nomadic races for centuries and which use a basic circular form and lattice frame with felt and rugs to create a crisp and useful living space.

Folding chairs hang from the ceiling in the folding and unfolding section - Tony O'Neill's Slimline prototypes hinge in the middle for easy storage, but this isn't a new idea. The "scissor" chair is actually older, and has an elegance and simplicity modern seating finds hard to beat.

Combining includes a beautiful set of Japanese boxes that can be used separately for carrying or placed together as house furniture. It's simple but perfect, as is the Shahsavan Mafrash from Azerbaijan, which can be a trunk, a cradle or a storage unit. Joe Columbo's Box 1 living unit dates back to the 1960s and includes a bed, wardrobe, table and chair.

The mobility of objects is something we now expect as an everyday function - witness the portable TV, now available as a wristwatch. We want to travel with our lives: cargo pants with multi-pockets, ultralight sleeping bags, a jacket that becomes a tent (Mark and Zana's Tentman). Nineteenth-century portable writing desks have been replaced with laptop computers. Once we are on the move we need to control our environment, so heat pads and mini-fans are standards, as is the Swiss army knife, multifunction mobile phones, torches and lighters.

This is an exciting exhibition but would have been improved by more information on individual objects. But the ideas it explores are fascinating, and the imagination of the designs makes you reconsider the opulence of life, and its effect on our environment. It's nice to note that Edinburgh College of Art students added prototype furniture that's funky and fun to the show. Living in Motion (part of the Six Cities Design Festival), City Art Centre, Edinburgh, until June 10.