In May of 2007, we went to Topaz Mountain with Troop 757 (we camp with them several times a year). It's a pretty nice area out in the Utah deseret, and allows mining of topaz crystals with hand held tools. The boys enjoy beating on rocks with hammers and chisels, clambering around on the face of the hill, and exploring some of the badlands in the vicinity. Here's a link to the album: http://www.facebook.com/album.
In June of this year, we did a 21 mile backpacking trek along the Great Western Trail. Along the way, we put in 2-3 hours of service, cutting back branches and vines that had grown out onto the trail (and in one case cutting and removing a log that had fallen across the trail). Two highlights of the trip (for me at least) were having a short snowball fight in June, and getting thanked for our efforts by a mountain biker who said he could really tell the difference between the trail we cleared and the other one he'd ridden that morning. Here's a link to the album for this trip: http://www.facebook.com/album.