I wear my collar literally 24-7. Well, except for when I shower, or when I have work, but they're the only times I take it off.
If I had a different job, I'd probably leave the thing on, but I work at Subway and thus, it's an OH&S issue, and I feel I should probably take it off due to that.
But I've never gotten any negative remarks, aside from the occasional drunken idiot asking "are you a cat, or a dog, woof woof" etc.
I get more remarks about the ears and tail, people hardly even notice the collar.
I just find it so much more comfortable, and feel naked and vulnerable without it, as opposed to vulnerable and fearful whilst wearing it. It's just part of me, I've been wearing it for so long, and I can't imagine myself without it. It's just a regular pet collar, so it's different to all the emo/goth collars, and I get remarks about it being different.
My really good friend got me a new dangly for my collar too, it used to be a little round Gir face (woo, Zim) that looked like a pet tag, but now it's a jingly kitty bell with a talisman attached. It's so awesome : )
I also have the registration tag from my old cat, so it's really not like a people collar at all and people just like it : )