h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Apparentl Marylebone has 4 standard accepted pronounciations.

Marley-bun
Marry-le-bun
Marley-bone
Marry-le-bone

(from memory, could be slightly wrong)

Perhaps I should have mentioned that in the article. The last 2 are the most common ones. I usually use the last one (out of habit really, but I think it must be closer to the original French pronunciation. Not that original pronunciations mean much for English place names). Really posh people seem to say Marley-bone, and occasionally you'll hear somebody saying Mairly-bone.

The pronunciation tends to get shorter the more contact you have with the area. Most Londoners pronounce it "ma-ruh-le-bone", whereas those who are actually from Marylebone itself tend to reduce it all the way down to something like "mair-bn".