To see what I have done by day (there is probably a way to limit it to a particular period of time, but putting that together is a low priority for me), here is what I do. Start with C-c a that brings up the orgmode agenda menu, then L to display the timeline for the current file and finally l to turn log mode on.
That gives me output that looks like this:
Wednesday 9 March 2011
Clocked: (7:21) One of my tasks
Clocked: (0:07) Another of my tasks
Given that this is in emacs, there is probably a way to make this simpler/quicker to use, but this is what I do at the moment.