When I first learned about soot blowers and soot blower function I had no idea there were different types of soot blower but when you read about the variety of applications for a soot blower, it's obvious there has to be different types.
Two types of soot blower that I have come across are:
The rotary soot blower (also known as a wall soot blower)
This is has a short lance and is generally used to clean furnace walls. Also used in the cooling sections of power generation plants, such as in economizers.
The retractable soot blower
This is a soot blower with a long lance. Usually used to clean ash/soot build up in economizers and superheaters.
I just read an interesting boiler corrosion Q&A on WikiAnswers where steam soot blowers got a mention. Someone asked: "What are the main causes of corrosion in boilers and their auxiliaries?"