It'd be a great idea to allow someone to answer their own question on the forums.
For example, I get frustrated sometimes and post a question to see what the community has to say about the thing I have run into. I then usually go back to working on the issue and sometimes stumble across the resolution before someone else provides an answer that solves it.
Currently, I am not aware of a series of steps that I can take after posting my answer to allow me then to mark my own answer as the correct one.
I think this would be a handy feature to have and would increase the hits on answered questions that are similar.