Now that Osama Bin laden has been killed (for the 12th time now), lets please say a prayer for peace in the world. There are apps in the Ubuntu Software Center than can help! (sorted by number of adherents)...
Xiphos Bible Guide
Minbar Prayer Times
Othman Quran Browser
Collection of Buddhist Sayings (display-dhammapada)
Hebrew desktop Calendar (hdate)
All of those can be found in the Ubuntu Software Center. I was unable to locate any apps for Hinduism, Atheisim, Rastafarianism or Scientology. If you know of any more good apps, please post them in the comments!
There are also some religious versions of Ubuntu out on the web. Give these a try also...
Ubuntu Christian Edition
Ubuntu Sabily (islamic)
Jewbuntu (i think this is fake)