What are the alternatives to Activity Monitor that will summarize cpu time over time? Activity monitor is not always good if you want to see what is keeping your computer busy for a period of time.

For example if you have gcc executed hundred of times it will take a lot of CPU power but the overall CPU time consumed by gcc will not appear. I'm looking for a solution that is able to count and summarize application usage so I can know that how the cpu was used.
I'm a huge fan of Bjango's iStat menus, which allows one to conveniently place various monitors (CPU, disk usage, network up &amp; down, battery, memory, temperature sensors...) up in the menu bar.  Each one can be pulled down like a menu for additional details.  It's a $16 app.  You can try before you buy.

Edit:  it looks like they have released another monitoring application called MiStat that is a separate app instead of living in the menu bar.  This allows them to place it in the Mac App Store.  It's available for a $4.99.  



Edit: I'm sorry, I must have not read your question carefully enough before I posted.  I do not know of any GUI tool that is able to aggregate CPU time being consumed by several similar processes as you describe.   The best idea that I can think of would be to write a script that wraps the top or ps commands and adds up processes that match a regular expression.   This strikes me as a market opportunity for a nice utility.   Could you describe a little more of how you would like such a thing to behave?