In WM6 we did a bit of work to make it easier to track your call history with a particular person. So, in addition to being able to see your entire call history you can now get individual call history from your contact card. This is a feature I'm particularly fond of, so I thought I'd point it out and run through the details.
You find this feature in the contacts card of someone you've called or who's called you. Just under the header you'll see a new field that says "Last Call". This field gives you information about your last phone communication with this contact:
If you action on this new field you'll be taken to a list of all your phone communication with the contact. More recent communications are at the top and each one indicates all the information shown for the "Last Call" plus the duration of each communication. From this list you can delete individual call logs, delete all call logs, or of course call someone back if you are feeling more generous :)
If you are trying to find out how many times your mom called you last week this would be the way to go, and you can even get to it from the call history list by actioning on a particular call to bring up the contact card. Of course you can still see your full call history from the dedicated app with calls to all contacts sorted by time. There you can filter for missed, incoming and outgoing calls as well.