Both London and Paris are big cities, orders of magnitude bigger than my home town - and yet the centers of both of these are all contained in an area within reasonable walking distance. Every city that grew out of a medieval hub maintains the core that was designed before motorized transportation was invented, even the comprehensively rearranged Paris.
Last night, I climbed up Monmartre - on foot; exhausting. Some nice pictures though. On my way down, looking for dinner, I got ushered into a tiny restaurant by a hyperactive landlady, taking my order without speaking a word of English. I'm sure I got wrangled, but what the hell - it was a very Parisian thing.
Big city navigation is aided immensely by the subway. It is an urban hyperspace, where seemingly impassable rules of traffic density, walking speed and map-reading ability are irrelevant. Since nearly all of Paris's landmarks are helpfully arranged in a single line, I started out in the morning with the Arc de Triomphe, then walked down Champs Elysee to the Louvre. Didn't go in - cues far too horrible, and I don't fancy looking at paintings all day; besides, it's a bit too Da Vinchi Code now.
Notre Dame next, then a subway ride to the Eiffel Tower. Got stopped by a street artist who wanted to paint me, then sell me the picture for 50 Euro. The picture wasn't very good, so I eventually just gave him a fiver - I'll consider it a tourist tax on the whole Parisian scene.
Crowd management at the tower is excellent, but it's still a lot of standing around, queueing. Got to go up to the top floor though. Didn't spit across the railing - too cliche.
I'd wanted to go to Harrods back in London - from what I understand it's a perfectly serviceable museum - but didn't have time, so I visited the Galleries Lafayette here. Wanted to look at the Archos gadgets in person. Ended up buying some cheese as the obvious souvenier - the hard, vacuum-packed kind that doesn't need to be refridgerated (apparently); I have to carry this stuff half way around Northern Europe, and I'm afraid that by the time I get home, anything more exotic would have achieved sentience.