>I've come to think of my instruments as functional works of art and keep almost all of them out where I can see them and pick one up if I have a notion.
"Functional works of art" is a nice concept, works for me... my first guitar/guitars were purely functional (did a job); later I bought a second one, also functional (slightly different sound suited to other material; useful to have a spare when the first one was in the repair shop etc.); after that they have moved into more of the "aesthetic" area - beautiful objects that produce a beautiful and insiring sound and are a pleasure to play. (As I mentioned above, I try to limit myself to three - acoustics that is - although not always the same 3!). Practical limitations are storage space / other priorities for discretional spending / how much money do I really want to have tied up in instruments / when is another one just duplication of a "sound" I can already get :) :) Also as someone else said, we do not really own them, we just curate them for a while until they eventually pass to someone else.
That said, if I could only take one to a desert island, which would it be...