the best way would be to reduce the size of the material.
I would use a chainsaw to cut the larger pieces and a chipper/shredder on the smaller stuff.
Beyond that I can't think of anything that would help speed things along.

As mentioned elsewhere, urine. If you aren't willing to go that far, coffee grounds.

Combine the two posts above, the two main things that will speed decomposition is particle size and Nitrogen. Also keeping it moist will be the third leg of your decomposition stool.

In very dry weather, sprinkle a little diesel fuel or lighter fluid around the pile. Step back, admire your work, and toss in a match. If you are not a vegetarian, bring hot dogs and marshmallows.

[Kidding!]

toxcrusadr, You ruined it by the "just kidding"!

Just kidding.

My friend Jimmy decided that this brush pile needed to be burned and that it was far enough way from anything flammable.

Well...the wind shifted just a bit...and four hours later with four volunteer fire departments standing by... the beautiful 100 year old barn was ashes. Jimmy said the heat was so intense that they might have been able to roast (tofu) dogs 100 yards away.

Burning brush piles is not to be trifled with. My boss had a crew in to clear brush and red cedars on a couple of acres and they left big piles that he left over winter. In early spring there was 1/4" of snow on the ground, wind in the right direction, and he decided to light one. Wind shifted and the cedar gave off so much flammable volatiles that a horizontal pipe of flame and smoke was extending many feet from the pile and almost lit his neighbor's standing cedar grove on fire. Up in the canopy it would have been pretty hard to put out. He about had a heart attack. Turned out OK though.

ladychips,

we have similar situation pile of pushed over trees (mostly hard wood trees with a couple of pine trees mixed in), we could burn but have chosen to cut it up with chainsaw and use it in the bottom of new garden beds of the raised sort the height of the beds is going to be the same as the width of corrugated roofing, we have a pile of over burden top soil to use as well. our method comes under the hugelkultur term.

len

Here is a link that might be useful: lens straw bale garden

All my neighbors (who are also kin folks) want to burn it. Heck, I want to burn it too...but it is way too close to my new house and right under some beautiful trees. Len - I've done some reading about the hugelkultur thing - sounds really interesting. I'll have to talk my husband into it (not so easy - can't even get him to pee on my compost pile...) Thanks for all the feedback. I'd love to hear more ideas if anyone wants to share.

Are we talking branches or large limbs? One could rent a chipper for an afternoon if it is smaller branches. Larger stuff could be hacked up and sold as firewood. People at the campground here are buying 6-8 chunks of split fire wood for $6.99.

Lloyd

Have you considered hugelkultur

While many people think of a brush pile as an eyesore those do have a place in our environment. They can provide shelter for wildlife, they can, over time, provide nutrients for soil, they can help stabilize soil that might be prone to erosion.
To hide that brush pile you could expend large amounts of time and energy and chip it and spread the result around as mulch without loosing all of the benefits of a brush pile. Burning material like that should never be an option because of the pollution burning produces. If you have something like a backhoe the Hugelkultur idea might work.

Burning wood is a problem with breathing in particles of toxic chemicals. I have never been a fan of bonfires. It seems like a fun idea as a child to go to camp and burn wood that you find, but now it seems like a horrible dangerous idea. Not just for burning your house town but cancer. Some many people in my age group 40's are getting cancer. People are know are dying from cancer.

If you want to use it, then renting a chipper, hugelkultur or firewood sound like great ideas.

If you just want it gone, you could place an add on Craiglist or Freecycle with the important words of "YOU HAUL!"

Burning has been around for millions of years, ever since there was dry land with vegetation. In fact, we've prevented it across large areas by putting out forest and prairie fires. I'm not saying we should burn everything, obviously, or that it doesn't 'pollute', but the occasional brush pile or campfire is not that big a deal unless you are in a very polluted urban area. Just my 2c, YMMV.

PS don't stand in the smoke.

We have all kinds of critters living in our brush piles. You just need to learn to look at them differently. it makes wonderful habitat for the birds, rabbits, minks, etc. I am going to try and get artistic with how I stack my brush. Weave patterns and conical shapes.

It would be great to hear from ladychips to find out just how long it took for this pile to decompose. I am willing to bet it wasn't more than 2 or 3 years, esp if any of it was chipped.

I had one particularly large brush pile from logging I had on my property. Limbs, blemished trunks, and a small mountain of chips from the saw on the knuckle boom.

I pushed it into a flat topped windrow and put a foot of fresh horse manure on top. I planted pumpkins there for 2 years. The crop never did well on this hugelkultur and I decided to do something else with this spot.

As I tore it down after only 3 years it was amazing to see how much had decomposed, and how dark and rich the surrounding soil had become. There were no leaves or twigs or anything smaller than 4 inches dismeter, and the larger stuff was soft and fungusy.

I read somewhere that Sepp Holzer's primary reason for hugelkultur was to be rid of trash wood and grow soil. I have had little success growing crops on a Richsoil.com type mound, but it sure grows soil.