I've found that when I (finally!) get back to Skyrim each day, I often find something like this: http://steamcommunity.com/profiles/76561198048861739/screenshot/522655154318290438?tab=public, head buried in the ground, shaft straight up, always the same kind of arrow (the ones with the reddish fletching - steel arrows, I think?). Does anyone else get this? A quick search here doesn't produce any results for something in the sky firing arrows at me when I load up the game. What is going on - have the dragons armed themselves? Is there some significance to these arrows?

There's a leg buried just under the surface.

I've encountered single arrows quite a lot...they do seem kinda strange but so far I've told myself that those have to be my own arrows that I've shot in the sky at some time... Does it only happen to you when you load the game?

Yes, I think so - I only notice them when I first log in but that might be because I've now got to the stage where I log and look around, thinking "Where's me arrow for today?"

TehJumpingJawa - it took a moment, but I got you in the end. V. poor!

Always one random arrow somewhere in Whiterun....I just look at as a minigame.

lol...every time I see this I can't help but think...Man I am Glad that missed me, does EVERYONE have to shoot straight up when firing arrows at the damn dragons??...lmao

I entered an ice dungeon I had visited before ...rounding a turn and looking up a slight slope...had to Laugh ..the Arrows looked like a slalom course..Skiing anyone?

those arrow are either fired by you or npc, everytime you re-enter the zone/cell where there are (fired) arrows leftover, they always appear in this manner.
you can pick them up, and they will gone for good.
or they (should) dissapear after sometime (dunno how long).