I have been looking for a mobile website builder because I am working in Papua New Guinea, where at present Internet coverage is patchy, sometimes slow and sometimes unreliable. However, it is a fairly safe bet that coverage, speed and reliability will improve and that most of the new users will access the Internet with mobile devices of some kind.. This is likely to also be true in many locations across the world.
Perhaps the best tool that I have found so far is Mobirise (http://mobirise.com/)and I would certainly suggest that people check it out. On the plus side, it is a visual tool that is very easy to use and has code blocks for picture galleries, slide shows, embedded video, slide shows and contact forms. Most of the work is done by a clever use of style sheets and Java Script but the resulting HTML code is clear and well laid out. It is fortunate that the program is easy to use since the developers have included no help system or manual, so be prepared to spend a little while experimenting by trial and error. All visual development tools offer a trade off between simplicity, speed, ease of use and flexibility and Mobirise is no different. At the moment you are stuck with a limited range of themes and code blocks, although the program allows for extensions there are not many of them available so far. You can tinker with the code that Mobirise produces if you have the skill but that negates the reasons for using a rapid application development tool in the first place.
This is certainly a program to watch and could well become a regular part of my tool kit if the range of themes and extensions expands.