One of my company's clients had a similar problem. They wanted to be able to extract lat/long coordinates from point shapefiles as well as center point coordinates from polygon shapefiles.
We ended up building our own software to do just that. The program is written in Java so it will run on any platform that Java runs on. It is a command-line tool that outputs the results into a comma delimited file with a selected attribute field followed by the latitude and longitude points. Our client is then able to import that information into the program or database of their choice. Our development team can modify the program to suit other client needs if necessary.
We retail the program for $100. I don't know if your need justifies purchasing a piece of software but I thought I'd toss it out as an option anyway.
Our company is PixSell and we are on the Web at http://www.pixsell.com. Feel free to contact us if you would like more information.
My name is Joel Lawhead and my number is 228-688-3391.