Gathering summary data based on two groupings

I am attempting to pull some logging information into a summary format.
The main fields I'm reading are the entry date, and the IP address.  I'm attempting to collect totals for the connect time.
Unfortunately, the data isn't exactly in order, so that presents my challenge.

I want to be able to insert a record in my database for each date that each IP occurs.
Example:

8/1/2011  1.2.3.4  60
8/1/2011  1.2.3.5 180
8/1/2011  1.2.3.4  60
8/2/2011  1.2.3.8  240
8/2/2011  1.2.3.5  100
8/2/2011  1.2.3.4  75

So based on the above data, I would want to have only 2 rows inserted for 8/1/2011:
  8/1/2011  1.2.3.4  120 (total of each entry of value 60)
  8/1/2011  1.2.3.5  180
but 3 rows entered for 8/2/11:
  8/2/2011  1.2.3.8  240
  8/2/2011  1.2.3.5  100
  8/2/2011  1.2.3.4  75

I've tried looping through the records but I'm having trouble catching when the date changes and/or the ip changes.  Granted, there may be times when both change as well.

I'd love sample code, but I think my biggest obstacle is the logic required...