Pros:
More control over your time and what you work on. Outside of client requirements/deadlines, you can scale back work if you want to focus on something else for a while. You can choose different work each time and keep things interesting.
Meet lots of interesting people. I find networking somewhat enjoyable. I wouldn't want to do it all the time, but I like meeting people and seeing what they are working on.
No office/team politics or dynamics to deal
Cons:
No office/team to collaborate with :) Being challenged with social issues is important and it sharpens your ability to communicate and work with people. You have to be really careful not to isolate yourself.
Variability of money, naturally. You need to track things to make sure you make enough on average
I would only do it if you find networking somewhat interesting and have a pretty strong network to begin with. I wouldn't do it if you don't already have a decent network. You can start that by blogging, going to conferences, and things like that.