If your church or ministry website uses WordPress, there are free and commercially supported plugins available that you can use to manage prayer requests.
List of Free Prayer Request Plugins
Commercial Prayer Request Plugins
Blazing Torch, the software developer responsible for PrayerBox, also offers the advanced version PrayerBox+ which costs $35 and a working demo can be viewed here.
The Prayer Engine is another commercial prayer request plugin for WordPress. According to the developer's website, "The Prayer Engine was built for simplicity. One click updates your Prayer Wall, RSS Feed, Twitter Prayer Chain and your Mobile Web App. No grunt work required."