I have converted my MTB for running errands and hauling my toddler trailer (for use the my 1yo and for various other hauling tasks). The flat MTB bars are slightly swept and very wide. I usually ride an aggressive geometry road bike, and frankly I find these bars incredibly uncomfortable after about 20 mintues. The bike has a 31.8 stem clamp, so drop bars would be an option, except it has MTB levers and shifters, and I don't feel like changing all of that. so it got me thinking, perhaps I could clamp something on that would give me more (and more comfortable) grip options.

standard bar end bullhorns are one option, and they are really cheap. I have also seen in photos on this forum that several of you run bar end drops, such as those offered by origin 8. this really appeals to me as I'd love to be able to get on the rivet and out of the wind, but I'm wondering if they are comfortable? do they line up straight when they are installed on swept bars? also, are they worth the money ($25-30) most places online. another option is dedicated touring bars, the full on upper case B looking giant bars, and those can be had in the same price range as the bar ends.

another option I'm considering is running the drop bar ends inside bullhorns on the outside, for tons of versatility, although it might look a bit weird.

before anyone bites my head off, yes I have searched. yes I have read reviews online. I'm asking for personal experiences. pros, cons, etc. I'd love to see pictures of some unique bar setups if you have them.

this is kindof what I have in mind. anyone running a setup like this? also I stumbled across a thread online where someone put aero bars on a touring MTB like this, and I do have a pair that would fit just kicking around. thoughts?

Just yesterday I saw on a different forum that someone got those drop bar attachments and was quite happy, but he said that it took a while to get it set up the way he liked. He used them for a completely different reason, he wanted to put a Rohloff twist grip shifter on the bar. See second post in this thread.
Rohloff shifter on bar end

look at Shimano XT m770 9speed or XT m780 10speed thumb shifters
and I am using Shimano XT m770 9speed thumb shifters on my Surly LHT

Figure 8 bend trekking bars give the up/down body posture by a near/far reach on the bars grips

and unlike the hard sharp corners of the bolt on things in the second post , the transitions are smoothly curved.

all the controls transfer without cable or lever changing.. though you may like a different stem length, etc.

I've been using and enjoying these Velo-Orange bars: Casey's Chromoly Crazy Bar, Noir - Handlebars - Components

Although I don't use the "horns" often at all, but I also haven't had many extended rides on them, yet. I find the sweep to be comfortable, though, and much better than the slightly swept back flat bar I started with. But I don't use drops, and I'm still trying to figure out the horns. I grab them every now and then for a change of position, but I think my whole set up needs a little tweaking, but it does seems like they'd be good for tucking in a bit. If I find that I'm not using them during all day rides, I'll just look for something that replicates the sweep, but lacks the horns.

This is my set up for my Schwinn CrossCut. Quite useful for me, as i can't stand using flat bar now for longer ride.

I'm pretty happy with trekking bars and plan to add some areo's to them.
I've left a little space at the bar end to add a computer on one side and a replacement friction shifter on the other if my index shifter craps out in the field. The cables are a little wonky because I just pulled a bag off the front.