Zend Platform (and a free T-shirt)
From the product information:
Through a centralized management console that proactively dispatches information to the applicable IT personnel, Zend Platform delivers comprehensive insight, run-time profiling, and performance monitoring, with an unmatched performance boost to ensure your business runs optimally.
The product can send automated alerts to the relevant employee when errors occur, and it logs information about the errors. A live demo demonstrates the user interface, showing statistics about incidences such as slow queries, peaks in server load, regular PHP errors, and inconsistent output sizes which could be indicative of other problems.
The software costs $995 per year for a single CPU license (a bit like adding $83 per month to your dedicated server costs).