Bob,
Try this

It looks for a change in the Cursor. When CamBam is thinking, it changes to an egg timer cursor, when thinking is finished, it reverts to the default cursor. This plugin beeps when CamBam changes back to the default cursor.
1. unzip and install BeepMe.dll in CamBam's plugins folder
2. start CamBam , it appears as a new entry in the Plugins Menu called "Beep Me"
3. set the Duration of beeping, it's in milliseconds
4. set frequency of tone, it's in Hz
5. check enable if you want it to beep
Edit: see below for new version