@Warsaw Will, you clearly are too obsessed with specialist book definitions and don't pay enough attention to actual use. Just because you can't hear subtle use variations doesn't mean they aren't there. My background is philosophy of language and symbolic logic, which is focused on uncovering the statements behind sentences, rather than being obsessed with the rules for creating sentences themselves. Trust what occurs in specific instances, not what general rules say. It's people like you that would tell TS Eliot to change "Let us go then, you and I" to "Let us go then, you and me" which would positively screw up one of the best loved lines in English literature, just because of your preposterous need to cling to the rules in all instances rather than using your ears and your mind and treating rules as the rough guidelines they are.

I am an American volunteering abroad to teach english as a foreign language in a country with a British curriculum so this issue comes up. There is a difference, but it is usually trivial. However, as with all trivial differences to a skilled practitioner of language it can be exploited to great effect. The "Got Milk?" advertising campaign example shows that got is often used in the context of acquiring. "Have Milk?" would sound ridiculous because there would be no reference anywhere to a context of acquiring milk and therefore milk is being treated as an attribute and this laconic question could only conceivably be asked to a woman about her own lactation. "Do you have a condom?" "Yes"…."Have you got it with you?" "No." Got and have are often about possession, and the fact is we posses many things that are not located near us. Usually the context of a situation makes it clear whether present accessibility is implied. When this is not the case, or when a speaker is being a literalist dick, "Have" refers to possession in the most general sense, "got" is used to focus attention on the specific situation. "Got" is temporally shorter than "have". "I have got AIDS," can by the literalist dick be contorted "Oh so you have gotten AIDS in the past, but its all better now, good to hear." Whereas "I have AIDS," is not subject to that weakness.