If I could, I'd go braless almost all the time - sometimes I really do enjoy the shape bras give me. Alas, the breasts are bigger now, so I can rarely get away with bralessness - and really, I never could because my nipples are more than a little noticeable.

I do go braless in our apartment building hallway, though. If I need to take stuff down to the trash room, I just wear a tee and cardigan, or a heavy shirt, so I'm at least a little more covered. When our dog was still alive, I did this, very occasionally, when taking her out to pee.

I just got back from vacation, where I stayed first at a friend's house, then with family. I planned my wardrobe so I wouldn't have to wear a bra with my lounge wear. At my friend's house, that meant just wearing whatever I wanted, because neither she nor her fiance cared if I was "properly" dressed. With family, it meant packing a cardigan so I'd have a second layer to pull over my tee.

I actually make it a point to go braless as much as possible--I think that it's healthier, because the lymph can circulate in the breasts better. I went to the mall today braless, although I did have a blazer on over my t-shirt. But I have gone braless with just a t-shirt, as long as the shirt is opaque. Some people do notice, and I will be stared at, but I guess I can't blame them. It's not a common sight.

I am trying to find more tops and dresses that work well braless. When you don't wear a bra, shirts don't always fit all that well. I do have a small bust, which makes going braless easier.

I agree that some braless-ness is probably healthy and when I responded I was very focused on appearance and my interaction with other people.
Christiane Northrup suggests that women not only spend some time without bras, but also that raising your arms above your head for a few minutes a day will encourage the lymph draining that Gigi mentioned.