Well I'm thinking about putting a rear locker in the Samurai, not for sure yet. Convince me one way or the other. I would like to be able to get a little more grip in grass/light mud without putting it in 4wheel. But I don't want to go through tires like crazy either.

I've never owned a Sammy, but the principles have to be the same.  First comment I am compelled to make is the type of tire you are running makes a big difference in the traction you do or don't have on any particular terrain.  Your tires have to hook-up to have traction, regardless of how many wheels are turning.  The second comment is a locker (like a Lock Right brand) is fairly user friendly if set-up properly in that if you are off the clutch or aren't accelerating in a turn... they will ratchet and allow the rear wheels to turn at the differing speeds more or less like an open diff allows.  So as far as burning up tires, I think that will be more of a driving style issue than a by-product of the locker.  If you nail the pedal into turns your rear axle will lock up and you will be spinning a wheel.  Spools will give you the constant wheel scour in turns because they can't differentiate their wheel turn speed differences.  Lockers are a good low cost way (compared to ARB air lockers) if you are wanting more traction in the rear of your truck. If you are careful and methodical, you can also set-up your locker in your rear diff on your own without having to reset the gear lash on your ring and pinion.   

Disclaimer: I have not driven a really short wheel base vehicle with a locker in the rear and if you will be driving on snowy roads and ice (as in a daily driver) the Locker may have more down sides than pluses to make it worth while to you. Mine is in a four door Tracker.

You'll be able to go more places with a locker than with just about any other mod.

That's what I like about the idea of having one, I can get in and out of situations where it's possible to go without a lift clearance wise but maybe not traction wise. I just don't won't to get stuck goin across a little creek somewhere. I figure a locker would keep me from digging a ditch with one tire and getting stuck. I had a Toyota pickup that the rearend was welded in and I went EVERYWHERE in 2WD but wore the tires down fast and it did jerk very little at low low speed, like in a parking lot. I posted a pic in the watercooler of how my samurai looks now so if you could just imagine it with a 1" lift and some all terrains that's pretty much the only suspension mod I want to do.

ARB air locker.
If you drive on the street you will not even know the locker is there when it is off. Flip the switch and it is locked solid.

It is not cheap but well worth the $$$.

I have run Lockrite, Detroit, and ARB lockers in my current dual purpose Sami and the only regret I have is not running an ARB locker from the start and saving a few dollars in the long run.

I don't have the money for the ARB but I would love to be able to get one.

I strongly recommend a spool or a locker, you mostly drive on the street so you should go with a lockright, 200$ for the lockright.

The only thing you will need to do is learn how to drive with it around corners. if your not tourqed they wont engage, but if your on the throttle they will engage.

you would be amazed at the difference being locked gives you.

Like I said, I had a Toyota pickup that had the rear welded so I know what to expect in corners when applying throttle. Thanks for all the help guys. I'll probably go with the locker, it's the cheapest and seems to be the easiest to install. I'll let you know how it goes for me.

I've always been told this by numerous people.
If your going to only use one locker put it in the front.

There is a really good thread on lockers you can read at http://www.zukiworld.com/forum/technical-discussion-beginner-repair/merged-%27lockers-the-best-but-most-%27-and-%27mini-spool-vs-locker-%27/

The discussion kind of goes everywhere, but has a lot of viewpoints on the various lockers. 

I strongly recommend a spool or a locker, you mostly drive on the street so you should go with a lockright, 200$ for the lockright.

The only thing you will need to do is learn how to drive with it around corners. if your not tourqed they wont engage, but if your on the throttle they will engage.

you would be amazed at the difference being locked gives you.

Agreed. Lockright front and rear here on 31 TSL's. Very easy to do and my truck will go over terrain (especially dirt/clay hills) so suprising i feel like im driving an atv.  It shocks me (and everyone else) everything we go off-roading in groups.

I just got done doing a mud ride with my new lockers front and rear.  It was like i couldnt get stuck no matter how hard i tried.  I ripped a 5 inch gash in my new 35s bc i didnt know i need to remove the rear bump stops. Lesson learned the hard way!

200 for the lockers, 100 for the rebuild kit and 160 for the install at zimmer.  So it cost me 460$ per 3rd plus 538 gears.  Well worth it, do it!