What do you define as a lot of cleavage?
Anything larger than a small D cup could be difined as 'a lot'. So 2/3 or more.
Are there times when you think a woman showing a lot of cleavage is inappropriate (for example: around children, at work, as a wedding guest)?
There are certian times when everything but the nipples can not only be distracting, but down right rude: church or anywhere religous; court, work or anywhere professional; memorials, funerals, or anywhere solemn; in front of obviously married guys.
Do you form an opinion of someone who is wearing a top that shows half of her boobs?
Usually, I figure they want something (attention, or more attention).
How does everyone else feel about cleavage???
I'm a big fan.