I'm looking for this exact same thing. I'd like to know all expenses in a specific project that are:

Billable

Non-Billed

There have been times where I've forgotten to check off billable on a Bill Entry. The only way I caught my error was when I collected all my  invoices and attached my invoices/receipts. Sometimes this happens months after a project is completed. Thank god I did it sooner rather then later, this would have been a $10K mistake for my small business. 

There needs to be a way print a summary.