I'm 99.9% sure this is a drug needle. A fellow board member got stuck by this sucker today. It's pretty sad when you have to look ouy for these. He broke the needle off before the picture was taken.
Newt
I've seen a few too, but haven't been stuck yet. I wouldn't worry too much, most of the nasty stuff that runs through your mind that you think you might catch can't survive being exposed to the weather for long.
I too have dug a needle in a plowed field before. I figure it was cattle vaccination related. I didn't get stuck by it, but let me tell you this: No pair of gloves can guard against those things.