There are actually different purposes to each of the different versions:
Within the Mobile Bible (http://www.mwbible.mobi), there are Advanced and Basic.
The Advanced version is designed for PDA's. It has more capabilities than the basic, and allows you to navigate as you please with drop-down lists and buttons.
The Basic version is designed for common cellular phones. If your phone has web capability, then you should be able to use the Basic version. It is a very simple, link-based interface that any cell phone should be able to handle. There is no search, but if anyone feels they could use it, send me some feedback.
Within the non-mobile Bible (http://www.mobilewebbible.com), there are also Advanced and Basic versions.
The Advnaced version uses a technology called Ajax to provide a richer user experience. That also makes it more complicated and heavy in terms of Javascript. Computers that have issues with Javascript or are on slower connections, should probably avoid using the Advanced version.
The Basic version uses less Javascript, and is more of a traditional web interface. You still have the navigation and search functionality, but it will act much like like a typical web page.
My original goal was to provide a means of reading the Bible from a smart device over the web. I had purchased a new PDA/phone with unlimited Internet, and could not find any web sites with the Bible that were formated for the small screens. Thus, I built one. After that, it just grew.