Custom Fields in Task and Projects? What about Sorting?

Two questions:

Is there a way to add custom fields to the Task and Projects?

I need a link field and large comment field. I am finding that the task and projects could be really useful for keep up on client work and invoicing them. However I need to store more information so that it is more productive for me. Love the fact that I can take the task and turn it into an invoice item. Those extra fields do not need to be tied to the invoice - its more for me to keep good notes on what to do for the customer.

Task View - Is there a way to change the sorting order in the task view? It would be totally cool to be able to click the column headings in any of the list view screens (tasks, invoices and such) to re-sort records differently. Oh that would make this the best app ever!!

Thanks for any advice.