Naked start.
Dump all your stuff, everything. I couldn't believe how much I had on me. Begin from Ansilvund in the east and race to Markarth in the west on foot.

No magic, no save except against a freeze. If you die you have to start again.
I had to run naked past my helicopter dragon that would not leave me alone, avoid a necro's fireballs, a sabertooth, a bear and a bandit chick who wants me to pay toll (I have no money remember). I got lucky and found abandoned weapons on the road, then into a cave to sneak attack some bandit babes for their hide armor. It was pretty fun.

lvl 62
45 min 14 seconds.
2 tries.

How did you do?

I might try this after I am done with everything else and I am bored.

Made me lol =)

Yeah, I'm saving this for later too.