I agree, a column added to enter time to a task in project view would be great. Optionally, a popup window that would pop up automatically upon marking a task complete that would allow the user to input time would be ok, as well. Anything to cut down on the number of clicks a worker has to do to mark a task complete and enter time from the project view would be very helpful.
While it's not a column in the project view, you can enter time on a task without leaving the project's task list. Select the task, then click the Summay Pane, from there you can scroll down and click Log Time to enter time, or at the top you can select Start Task/Done/etc.
I'd love to see this displayed inline with tasks. Having this option at first glance would provide valuable information about who has logged hours vs. who has not. Second, it reduces the number of clicks they have to make.