Ok, I got curious, and wanted to know how much our supposed log would weigh, just as an intellectual exercise. Took some searching, but here's what I found:
http://www.woodweb.com/knowledge_base/Log_weight.html
"The log weights in KOCH that I mentioned are based on 4800 logs. Some sample values are for a 16" x 12' log of ash, 1010 pounds, hickory 1267 pounds, soft (red) maple 1059 pounds, red oak 1323 pounds, white oak 1262 pounds and yellow poplar 1262 pounds. Of course, there are numbers for other diameters and lengths. As the volume of such logs in this example are 130 BF (Int.), 120 BF (Scribner) and 108 BF (Doyle), you can figure out weights per MBF log scale too." [BF is a reference to board feet, which is 1"x12"x12"]
I couldn't find any charts or anything which gave an example for 6"x12 feet, but if you divide the 16" log discussed above by 3, you get a log about 5 1/3". If you take the average weights of the above listed logs of various woods, you get about 1200 pounds. (1197 if you wanna be technical, but even numbers work nicely.) Since we divided our diameter by 3, we now divide the average weight by 3, and come up with 5 1/3"x12' of log = 400 pounds. Could you carry it? No, but I know that if I had to, I could drag it. Wouldn't be fun, and I'd probably have to take a breather every 50 feet or so, but I could do it. Not to boast, but I'm pretty strong, not sure if many other people I know could do it. I don't think I could get a half mile or whatever the distance was with it though, unless I was given a whole day.