Redmine

This is the feature i'm going to work on for the next release.
So if you have any requirement about this feature, let me know.
Best regards,
Jean-Philippe

Also ability to add time per project in general would be essential.
I think time tracking systems that are too built around specific
tasks end up not being used.

I would like to use redmine for our firm's time tracking , but
if time has to be tied to a task it won't be used, I prefer to
be able to say on this day I worked 8 hours on this project,
and that's that. Rather than 2 hours on this task, 4 hours on
this, 2 hours on that task, etc.

I think you could have both ways pretty easily though.

I've just committed the time tracking functionality.
It's just simple for now (for fancy reports yet).
Time can be logged at issue or project level.

To enable time tracking on an existing redmine install, check
out the trunk, migrate. Set permission to log time for your differents
roles (Admin > Roles & Permissions, you'll see a new
"Time tracking" section on the role screen).
You'll also have to specify some "activities" in Admin
> Enumerations.

Now, when viewing an issue, you'll see the total time spent on
that issue and a link to log time. Total time at project level
is shown on "Reports" screen (only if time > 0).