Web Development for Mobile:

There are a lot of approaches when it comes to web development for mobile. In the end I believe it comes down to "fitness of purpose." You have to decide what will be best suited for your audience by looking at how many mobile users you actually have and how best to serve not just them but all your users.

• Great Podast about Mobile Web
  Really enjoyed listing to this podcast about the state of the Mobile Web.
• Responsive Web Design
  A good article from A List Apart about "Responsive Web Design" as it refers to Mobile.
  
  The Summary:
  A media query allows us to target not only certain device classes, but to actually inspect the physical characteristics of the device rendering our work. Fluid grids, flexible images, and media queries are the three technical ingredients for responsive web design, but it also requires a different way of thinking. Rather than quarantining our content into disparate, device-specific experiences, we can use media queries to progressively enhance our work within different viewing contexts. That's not to say there isn't a business case for separate sites geared toward specific devices; for example, if the user goals for your mobile site are more limited in scope than its desktop equivalent, then serving different content to each might be the best approach.
• Yiibu.com
  Authors of "Rethinking Mobile Web" they give an excellent presentation that turned a lot heads. The main idea is designing for Mobile first and desktops second.
• CSS Grid
  Fluid web design down to Mobile.
• Phone Gap
  Open Source Mobile Framework.
• Less Framework
  Less Framework is a CSS grid system for designing adaptive web­sites. It contains 4 layouts and 3 sets of typography presets, all based on a single grid.
• Media Queries
  A collection of responsive web designs.