I closed the loop up once it got to be 30 rows long. It was four rows wide, and since there's also the offset rows that should mean there are 240 rings in it. I'm going to make a wild ass guess that i've spent about 5 hours working on it (almost 2 hours at the con, about an hour and a half at the call out and call back, and an hour and a half tonight) which would be about 300 minutes. So slightly over a minute a ring. I _think_ i'm getting faster at it though, so perhaps that ratio will go down some.
As long as i'm measuring stuff, i left the Coffee Cartel at 10:32, and got back here at 10:45, so with the minute i spent waiting at the intersection that comes out to about 12 minutes. Moogle claims it's 0.9 miles between here and there, but it might only be 0.8 since i took a slight shortcut. So that means that if i'm trying to walk fairly quickly i go about... somewhere between 4.0 and 4.5 mph. Of course at that speed i start developing blisters pretty fast, so i couldn't keep it up for long =P