Be able to choose whether a category be included in summary report

Be able to choose whether a category be included in summary report...either as part of reporting or tied to a category as a whole (like the tax deductible slider in category settings).

There may be other reasons for this as well...in my case I transfer money between accounts and thus these aren't really expenses and so I'd like to exclude them from the one chart that shows where money is going to better reflect actual spending.