A friend of mine posted the following pic on Facebook, wondering what the mysterious pipe-like object between the flaps is? Note the thin metallic object sticking up at an angle just where the wing angles back.
My theory was that it’s for dumping fuel, but turns out that the B757 can’t dump fuel, so no go there. What sayeth you, dope?
It looks like it could be a vortex generator, but it’s odd that it would be mounted on the trailing edge of the wing rather then the front.
Perhaps it is something similar to keep the airflow smooth over and around the edges of the flaps?
Here’s a hi-res pic of another 757 wing without the object.
Hm, you linked back to this thread =)
It was for nostalgic reasons.
Meanwhile here’s a hi-res pic of another 757 wing without the object.
Your pic says that it’s a 737.
I believe those are for dumping off static electricity that builds up during the flight.
ETA, if that is what it is, “Static Wick” appears to be the proper name for it.
That doesn’t look like a static discharge wick. Length and location is wrong for a 757 wing, AFAIK.
Could it be the fuel vent? (I’m guessing not, but it does look a little like the fuel vent of a Cessna 177)
Brian
I asked a on another message board full of people knowledgeable on such things. Here are the responses so far:
I’m inclined to believe the last guy. 
What makes them say it’s a 737 and not a 757?
I’m looking at photos of both airliners, and AFAICT, it’s definitely a 757 based on the configuration of the spoilers.
http://www.the-blueprints.com/modules/vectordrawings/preview-wm/boeing_757-200_winglets.jpg
Note the 757 variant with winglets has spoilers in a constant line across the wing with no gaps.
The 737, on the other hand, has a “gap” in the spoilers, a section that doesn’t open up.
Every photo I’ve found seems to bear that out. So I believe this is a 757. I still don’t know what the tube is, though. 
Thread FAIL. 
Whether it’s a 737 or 757 wing doesn’t really matter in this case, there should be nothing sticking out between the two flaps for either aircraft. I think the first answer that StrangerThanFiction received on that other forum is probably the culprit, a protruding gap seal.
I think you’re right - a flap gap seal that got bent and pinched during flap retraction. I also agree with Blakeyrat that it’s a 757, judging by the spoilers and flap canoes.
A slow Cessna.
~VOW
It looks like there could be another one that is not sticking out in the middle gap: http://img46.imageshack.us/img46/4339/snap1wu.jpg
(and yes, I know it looks professionally done, but, believe it or not, I circled it myself)
I think that’s just the spoiler not sitting flush against the wing, the back end is bumped up about an inch or two.
