Speakerectomy is by far the most brilliant solution to the audible bell problem. As its name implies, it consists in removing the beeps by removing the beeper. The operation is straightforward and you don't even need any anesthetic, but if you want there's room for refinement.
PC's are usually equipped with a silly switch to lower CPU clock. The switch is never used when you work in a multitasking environment, as you don't even need to slow the computer down to run games based on software loops. Unfortunately we can't use the switch to increase processor speed, but we can use it to enable/disable the loudspeaker. Sometimes the speaker is useful even if you enjoy a silent number cruncher, for example to signal the end of a lenghty compilation. To modify the switch functionality, just detatch it from the main board and connect its wires in series with the loudspeaker.
Owners of laptop boxes, unfortunately, don't have easy access to the loudspeaker, and neither they have a spare switch to turn to a different task. The preferred solution for such users is configuring their software to avoid beeping, as described below.