Particularly for existing clients, it would be helpful to be able to change an opportunity into a project. Because this is an existing client, I'm not going through a formal proposal process or anything. I enter projects as opportunities until I receive the official work assignment from them (I'm covered by an annual agreement, so there isn't a new contract every time), but then have to create a new project once that assignment is received.

It looks like I'd also have to go back to the opportunities page to set something as complete, even if I mark the project complete? (Again, projects for existing clients)