Several consultants had came in and told the CEO that there was no way to graduate out of the system, that it would require a total rewrite of the system. The CEO had went through 3 failed attempts to build a new system with external vendors the second of which folded shop and then the CEO got a call from an Indian company saying that they had been working on the system for over a year and had not goten paid. Apparently the front company that folded was subbing everything to offshore firms without letting the customer know.
Anyway, all attempts failed and the one most critical business issue was that the rates and allotments for hotel rooms needed to be available to customers like Hotels.com, Travelocity, and Expedia in real time. It was a read only problem. I set up an export from fox-pro to a database cluster (I can't ever remember which one now (Oracle or MSSQL). Built some web services on top of it to expose the data and published the WSDL. All tolled we (2 people full time) spent a week building the services and added over 30 million in revenue, the first year. I have done some others, but that is probably my best time to money ratio of my career.