I was Wondering how could I carry around some Line On my person for emergency purposes and figured out to just stick 6 feet of twisted (Dont go for braided) Nylon mason line and a roll of Floss in a altoids small tin.

Paracord Items such as bracelets and shoelaces are good too but While I Like the idea of paracord My preferences is Twisted Masonline.

For line of that size and lenght, i will often use a small zip lock baggie. Works very nicely. I,too, like braided mason's line.

The Brand I Purchased states 12 pound test and Can easily be split up into 3-6 strands depending on how thin you are willing to use it for certain tasks so twisted over braided is my thoughts. I Must Switch out the braided in my survival kit for this stuff now sadly its gonna be tough to tightly wind it up again.

Will only 6 feet of cord be worthwhile? I've been using 'decoy anchor line' from Cabela's lately. It seems strong enough for a quick shelter and doesn't take up as much room in the pack as does 550 cord.
If that too large, say for a PSK tin, try 'suspended ceiling leveling line,' from Lowes or Home Depot. It comes in a plastic wrapped hank of about a 1/2 inch in diameter and 4 inches long, with about 450 feet of line if I'm not mistaken, and is surprisingly strong. I thought it would be fine for lashing one of those cheap plastic 'painters drop-cloths' overhead as shelter.

I always try to carry two Pieces. One in a pocket (about 2m of good quality cord) and one around my neck with my Mora Knife Attached as a backup. If I have a backpack or day-pack I often back it up with a longer piece and a small roll of very thin wire.

Usually 3-10 m in a backpack. ( and 10m of floss in my briefcase)

I use orange paracord from countycom.com. I cut 100' hanks into SIX 16+ foot lengths. Then I wrap each one around my hand until there is about 5ish feet left and then I'll wrap that around the middle of the bundle and finish it with a clove hitch.

I learned that from my father and have done it that way for a loooong time. It works for me.

If I am using a fly with a thicker "ridgeline" I'll carry a longer longer line.

On very much of a mildly related side note ...

I really like the setup instructions at http://www.cookecustomsewing.com/tundratarp.htm . This influences what I'll carry if tarping.

I tend to keep little notes for myself in Google Docs, and here is the note I made when setting up my Tundra Tarp:

Tundra Tarp Setup

Permanently Attached:
>>16" pieces of 1/8" poly line to each fabric loop along perimeter and face of tarp. (poly doesn't stretch like paracord)
>>12' long piece of 1/8" poly line attached to center four-loop attachment point. Make a 12" bowline loop at the end (24” circumference), run the loop through the four center loops and then back through the end of the 12" loop, then wrap the rest of the cord down the center pole and stake to ground.
>>Corner Cords (if none permanently attached):
>>Four 30" pieces of 1/8” poly line for prusik knots

Carry:
>>Two 50' lengths of 1/4" poly rope for ridgelines.
>>150' of 1/8" poly line cut into nine 16.33' lengths.
>>50' of sacrificial 1/8" poly line that can be cut as needed.
(note that the two above adds to 200' total == two 100' hanks)
>>Two collapsible 8' poles