1) Be able to send Statements of Work and let clients be able to approve them, and track the status of these SOW, be able to edit old ones for clients that want to add stuff under the same SOW and send out again to re-approved. This is a major pain in the butt for me.

2) Also, the ability to add stuff for billing by just maybe clicking a checkbox next to items that are sorted by client. For example, I add a new task, and mark it as billable. When I go to an invoice page, I can just click on the billable tasks for that project and/or client and add them to one invoice.

3) Track the status of these invoices.

4) Manage contracts - one or two clicks to send a contract template for those clients who prefer digital format - ability to send in different formats would be great too - Word, PDF, normal TXT (txt might be useless though).

5) Of course, manage clients and projects. I could probably add a hundred features here but I think thats enough to get you thinking