Lazy Korean,
before you worry about content or indeed layout , you should empathise a managers position. If he/she opened a letter from a prospective employee then it would have to be very appealing for them to look at it long enough for you to get that much needed call.
I suggest you create an elaborate letterhead/margin document with a generalised few paragraphs about yourself and why you want employment with X persons firm. Make sure your document (thats what i like to call it) is professional, no spelling mistakes and try to make it original.
I have a resume that features a thumnail pic from my latest black tie event on a pine green letterhead/margin layout: It looks professional but a little too professional for the kinds of jobs we are after. Always consider what job your applying for and try to make it relevant.
Bear in mind: People will always say its the content thats important but rarely will employers overlook a professional, colourful document from someone committed enough to make it.
If you want some more ideas or a look at my work, dont hesitate to PM me.
My $0.02