Caterpillar Skid Steer Tractor
When we decided to build a house ourselves, we realized that we would need a tractor of some
sort to move dirt and materials around the lot.  We settled on a new Caterpillar model 252 skid
steer tractor from
Empire Southwest in Mesa.  These machines hold their value really well, and
the new one was not much more money than a used one in good shape.  It is rated to lift 2400 lbs,
but I'm pretty sure I've had more than that in the bucket as I moved rocks around on the site.  
The thing is simply a brute ... fun to drive also.
We bought several attachments for the skid steer, such as a toothed bucket, a set of pallet forks,
and a backhoe attachment.  The backhoe attachment didn't look very heavy duty, but we figured
it would help out on some of the trenches.  Much to my surprise, the backhoe turned out to be a
lifesaver.  It wasn't the easiest thing to use in tight spaces since it doesn't pivot like more
expensive ones do ... we had to drive and pivot the entire tractor as we dug the dirt and dumped
it to the side.  It has proven itself to be indestructible (so far), however, and we lifted out some
huge rocks and busted up others with it.  It digs a pretty ragged trench because of all the rocks
we have, but in decent soil it worked very cleanly.

One of the side effects of the skid steer action is that I would mess up the layout lines on the
ground as I dug backwards.  I solved that problem by placing some stakes well out in front of me
that were aligned with the layout lines.  I simply sighted along them as I moved backward.