All right, where's the best place to buy a gooseneck coupler lock?  And, what type should I buy for this type of coupler? 

Sorry the pic is so small, you probably can't even see what you need to see.  I can take/post another pic if I need to.

Two locks....one over the end of the gooseneck coupler, and one on the bolt heads of the coupler set bolts on the stem. 

http://www.lowcosttrailersupplies.com/Trailer_Parts/a-eztl5051-40ka.html

Seriously??  Over the BOLTS?  I'd have never thought of that.    And I'm not sure I can afford that right now.

Let's have a poll, who here has just the coupler lock, and who here has the bolts locked up too?

Here is the best way to do it. Can't move the trailer this way. With a coupler lock, you can still move a trailer. Any of these should work.

http://www.tirelock.com/

or http://www.kiramek.com/english/products/worch/index.html

or http://wctproducts.com/immobilizer_menu.htm

or http://www.trailerlock.com/?gclid=CLmx1fHDlJMCFQwRFQodgyAlew

READ THIS BEFORE YOU BUY ANYTHING!!!

http://www.horsetrailerworld.com/forum/thread-view.asp?threadid=7911&start=1

I looked at everything everyone posted here and in the other thread, and I believe this is what I'll get:

http://www.trailerlock.com/index.html

Thanks everyone!!!

Edited to remove the smiley that I didn't watch long enough to see that it's not REALLY just three people smiling happily.  (ooops)

By the way, I just heard from the MFR (I think) of the Trailer Bullet.  Their price is lower than I thought... $65 for one, and a little less if you want to become a distributor and you're able to buy several at once. 

This product looks equally effective TO ME, and it's $5 to $25 cheaper than the wheel lock I just posted (depending on whether the wheel lock's sale price is active at the time of purchase).

http://www.trailerbullet.com/trailer_bullet.htm

Comments?  Who likes which of these two products better, and why?

As long as you don't let the drop leg out more than a hole or two on your jack, it will work great. Otherwise throw down a floor jack, jack it up, raise the foot, drop it on the truck, and take off. Less than 5 minutes. Same thing goes if you put wood blocks under your jack legs. Lift it up, move the blocks, lower on the truck, and take off.

So many people drop there jack leg 3 or four holes, or don't drop it but use a 6" block under it, that the jack lock won't work on those trailers. A floor jack will fix all their difficulties, and probably speed things up if the are ready. Think about it, these people aren't running a long ways, they are going just down the road and then hooking up right and taking off. Nobody will look at them twice unless someone knows your trailer.

OK, to get it off my property the thief would need to navigate a short but significant hill/dip.  If I use a thin plank instead of the 4x4 block (just because I can't stand the thought of putting it directly on my paved driveway, and neither can my hubby), and drop the leg as much as it will go, then will this work? 

At home is where the trailer is at greatest risk... I'd like to see someone TRY and steal a horse trailer from one of our local Endurance ridecamps.  LOL

No, I meant don't. The lock only locks the ability to crank the jack. If you raise the trailer 1" and then raise the drop leg approximately 3" for each hole, you are gaining ground clearance. You can navigate a lot of places with 6-8" of clearance. If you drop your leg 1 hole, and set it on a 2" board, when you raise the foot you will have 5" clearance...2 holes will be 8"...3 holes will be 11". All of these are approximates, but you get the idea. If you use the thin plank, it will help, but most people will use as many holes as possible, or use a big block, to have to crank less.

From error on my part, it was amazing when I learned how far I could take my trailer with the jack leg only up 6-8".

I feel so dense.  The way I see it, the more jack leg that is extended, the LESS clearance there is when the trailer is hooked to a truck... because the leg is stuck hanging down there.  

If the lock secures the jack leg so that the leg cannot move, and if I leave the front of the trailer so that it is higher than or equal to the height of the ball of the truck, then how can someone even lower it far enough to drop it onto the ball of a truck?  I guess they could come along with one that's 10" higher than my GMC, and THAT would give them some clearance between the foot and the ground, but damn sure if they bring in anything close to the height of my ball they're going to have a hard time getting the coupler lowered onto the ball and still having room between the jack leg and the ground. 

Clearly you disagree, so what am I missing?

Floor jack, bottle jack, hi lift, any other jack that is portable. Stick it under the trailer, lift the weight off the leg, raise the drop foot, and lower it on any truck. Drive away.

That's just it though.  HOW would they raise the drop foot with that lock on there?  I don't get it.   

If you have a jack leg with a spring foot, it will snap up when you pull the release pin. How far will determine on how many holes the leg was extended.

Gard