Since Ryan hasn't chimed in yet, I'll tell you about the ones I know about. All of these are in use in the Jackson Hole area:
Avalauncher: a compressed-air gun that fires (I think) a one or two-pound charge and has a range of probably up to about a mile. Very good for short-range shots and smaller charges. http://www.avalanche-center.org/Education/glossary/
At the Jackson Hole Mountain Resort, one of these is mounted permanently near the top station of the Thunder Chair. It's used to do control work in the Cirque, Tensleep Bowl, and the Headwall. The avalauncher fired this unexploded projectile that I found on a hike in Tensleep Bowl last summer:
Recoilless Rifle: a semi-portable artillery piece that fires either 75mm or 105mm artillery shells. These are sometimes used for temporary control work and sometimes mounted permanently. At JH, they used to use a 75mm rifle to shoot the shoulder of Cody Bowl for the Powder 8 National Championships. I don't know if they still have that gun or not. Here's a set of photos (from the Bridger-Teton National Forest Avalanche Forecast website) of an avalanche that was triggered in Cody by a shot from that rifle:
105mm Howitzer: This is a not-very-portable-in-the-mountains artillery piece that fires larger shells. These are used when a BIG explosion is called for. There is a permanently-positioned one at the base of the ski area in Teton Village. The patrollers have recorded all of the coordinates of the trigger points of all the main slide paths inside the ski area so that the gun can be fired in periods of low or no visibility. It was this gun that triggered the infamous Headwall Slide in 1986 that ran nearly top to bottom inside the Jackson Hole ski area (and I was an eyewitness
Cable Slides: This is just a rope-and-pulley arrangement that allows a patroller to run a hand charge out over a trigger point and detonate the explosive at a distance that is further away than a patroller could safely throw the charge. There are several of these constructed over chutes and cliff bands around the ski area.
Propane Cannon: This is a very interesting device that allows remote detonation of a large slide area. I don't have a good photo of one but there are four of them located on Glory Bowl above Teton Pass. Basically, it's a large steel pipe that is angled up about 20 feet and then curved back down toward the snow surface. A large chamber inside the pipe is filled with a mixture of propane and air and then ignited remotely. The explosion is directed out the end of the pipe and downward toward the snow surface. During the fall, the Wyoming Highway Department hauls huge propane tanks up the mountain and connects all the plumbing so that these cannons can be completely operated by remote control during snowstorms. No one has to drive on the pass or hike up the mountain during high avalanche hazard.
Charge Slinger: I actually have no idea what this gizmo is actually called, but that's the name I'll use. This is almost a brand-new idea, again being used on Teton Pass. Again, the idea is to be able to deliver explosions remotely. It's kind of hard to describe, but think of a Coke machine that's loaded with explosive charges instead of cans of soda. Also think of a trap machine that flings out clay pidgeons. This device can arm and throw explosive charges out onto the snow service and it can be operated completely by remote control. It seems like kind of a Rube Goldberg contraption to me, but the Highway Department seems to like it.
Those are the main ones that I know about, but I'm sure there are many, many more. The possibilities are practically endless.