There's personal value intrinsic to objects you have had a part in creating, I think having something truly unique in the world is fantastic and I am hoping to incorporate this into my lessons when I start teaching. Students build websites and such already but I've not seen any really take ownership of their creations, perhaps this is a value only for physical objects? Perhaps 3D printers can change this? I have a few photo mugs but I've never tried designing my own, but now I very much want to.
I actually used an online photo printing service offering 25 free prints so I printed out screenshots from Star Wars Galaxies so I could remember the time I had with my friends. I had completely forgotten that until now. I've never been one to keep digital cruft for too long, every so often deciding "I have nothing of worth on here, just reformat it all" and it's only some time after I realise what was lost. As you said, it can all be deleted with one click, so ownership (and pride) of things digital can be fleeting: a mixed blessing.
I couldn't name the sites I used to visit, but there is one that I ran. I built a forum for my Star Wars Galaxies guild to use, that was probably were I spent all my time: discussing the game, our lives, the news, and the future. That friend group developed really well both in and out of the game. We later tried migrating over to Star Trek Online but the game never lived up to the designs they were telling us of (I think another company took over?). We'd filled this forum with long discussions of what we wanted, how we thought it would be, and had lived futuristic adventures vicariously through text and our imagination, all for it to be lost as we turned away and moved on with our lives. I don't think I could put my feelings on that past on to a mug; it seems silly but when it was such a huge part of my life at the time it hurt to have it end with such a... fizzle.