Trenches, Post Hole and Form drilling with hydraulic auger (6in, 10in, 14in, 24in bits). Frost is no problem.
Stump removal, woods cleaning, trail work. I have a mixer for the auger as well that can mix 4 bags at a time and then I can dump it directly into forms.
Regardless of if you have me do it or not, call Dig Safe http://www.digsafe.com/ ahead of time and have them come out and mark any utilities. They usually want a 2 day lead-time, it is free and you won't find any insured people that will do the job without calling Dig Safe first (it is a requirement for commercial liability insurance in NH). If they don't mention Dig Safe, look out.
I am in Merrimack and will travel locally. I am fully insured and I charge by the hour. To keep the payment simple for everyone, I prefer to be paid in cash.