hardwood floor installation project, with pics! Options

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so as some of you may know, i install and refinish hardwood floors for a living, and since i had some left over wood from previous jobs, i decided to install some in my living room.
i have done many "straight" install jobs, where the boards are just layed side by side, across the room, and figured it'd be a good chance to try somthing a little more difficult.
so, i decided to try a "border-laid" configuration, where you create a border around the center of the room.
here are the results:
first, a couple pics of the pre-exsiting floor:



this floor is OLD southern yellow pine, very typical in this area, and mostly used as a subfloor. the gaps between the boards are quite large (some over 1/4") and that would let cold air thru from the basement (i live in a 1st floor apartment) not good in the winter, at ALL. lol
i had some red oak left over from previous jobs, so i decided to use that as the border, and "mill-run" maple as the center.
so, i layed down some 30lb roofers felt, to cover the gaps, and to help stop squeeking ect later on down the road, and started laying the first board:


then continued on with the border from there:

a close up of the border:

once the border was laid, i started filling the center with the maple:

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thanks for the props guys.
your right, its a great feeling when you take a crappy old floor and make it new and fresh again..installing is nice, its decent $$ too, but 90% of my buisness is refinishing old floors, and thats where the real instant gradifacation comes in...you take an old, beat up and run down floor, and make it look like new again...its the part of my buisness i like most.