Mobify, for example, takes the URL of your regular website and lets you select the crucial DIVs with a neat visual editor. Then you can test the result in several different sized screens and, if you're satisfied, push the button and go live in several minutes. The tool scrapes your site and republishes the information from the selected DIVs.
Similar repackaging services include Mippin's Mobilizer, which is is integrated with AdMob's ad network; Onbile and Wirenode, which have some mod templates; Winksite, which integrates a basic community network next to your content; Mofuse, which has QR 2D bar codes integrated with a URL shortener; and Yahoo's Blueprint, which is tuned for "thousands of mobile devices," including the iPad.
All these sites are regularly adding new features and will undoubtably imitate the best innovations of their competitors. Using tools like these simplifies the process of creating a website dramatically. The downside is that all the websites from one service have the same flavor, and there's little opportunity to move too far afield. Although the structure can provide a fair amount of flexibility, especially if you supply your mobile site with an RSS feed from your main site, there's still the potential for being locked into a plan.
Path 3: Plug-ins
If the screen-scraping repackaging sites just pour the data into a different template built out of HTML and CSS, there's no reason why you can't integrate such mobile-optimized HTML and CSS into the main website to begin with. Doing it is not as simple as delegating all of the repackaging to another website, but it does bring more control.
In many cases, it's often relatively easy. Some Drupal plug-ins, for example, automatically detect the browser sending the request, then automatically chooses the right template, which may be a simplified one designed for mobile phones. The iUi plug-in uses the iUi interface library to format the content for the iPhone and others WebKit browsers. Others such as the iDrupal UI, Mobile Tools, and Mobile Plugin follow a similar plan.
There are several related plug-ins for all the major CMSes. WPtouch is popular and has a proprietary version that costs $39. Joomla users can turn to TapTheme for similar skins that work with iPads as well.
All these approaches offer more control than any mobile repackaging site. The code is generally open source, and modifications are both often possible and usually feasible. When the modules are well-maintained, this approach can offer most of the advantages of a hosted mobile repackaging site with the control of owning the server. But if the module developers get called onto other projects, the work falls onto your shoulders.
Path 4: Commercial products