present simple and present continuous

[Longrob]

My understanding is that the present simple tense is used to indicate a habit, state or ability, whereas the present continuous indicates a current (often temporary) action or a plan for the future. Can someone help me to explain the following example in those terms:
I live in London, and
I am living in London.

Personally I can't imagine ever saying the latter, but I can't find a satisfactory explanation, in grammatical terms, of the difference.

Thanks
lr

[Mister Micawber]

.
I live in London-- a simple statement of location of residence.
I am living in London-- As above, but with a suggestion that the residence is new or temporary. Continuous is also often used when the speaker has a heightened interest or concern about the topic.
.
_________________
Native English teacher at Mister Micawber's