Here is another great partner, Mobile Entree.
Mobile Entrée (ME) is a SharePoint Solution that is installed on your SharePoint Farm. At it's core, ME provides a framework to build mobile applications within SharePoint Features.
Out of the Box, ME provides a mobile application we call the Base Plugin. Using the Base Plugin, you can configure mobile access to SharePoint lists, document libraries, discussion boards, and search. This base plugin can also be used as a menu to display any number of other mobile applications on the site.
Mobile Application Framework
ME utilizes the mobile web browser as the client delivery platform thus making it, by nature, cross-platform. Because they live 100% in the application tier, your mobile applications have access to all the same enterprise resources as your custom webparts or other LOB applications.
Mobile applications built upon the ME framework are developed in Visual Studio as SharePoint Features. They can even be included in the same Visual Studio projects as your custom webparts or workflows. By taking advantage of the tools that SharePoint developers are already familiar with, the learning curve for developing on the ME platform is very short.
There is an emphasis on best practices for custom development for SharePoint. Mobile Entrée as a product fits in by being installed and managed centrally as a SharePoint Solution. Mobile applications built upon the ME framework are also installed and centrally managed as SharePoint Solutions and Features.
Mobile Entrée does not do anything outside of what SharePoint does in terms of security or authentication. One issue that may arise is the ability to get access to SharePoint that is behind the firewall. There are a number of companies that provide this capability like RIM, BitKoo, GOOD, Microsoft Forefront UAG as well using the mobile VPN capabilities on newer smartphones. Our focus is on the application side and would point to one of these solutions for mobile access behind the firewall.
Here is a quick demo that I presented at the SharePoint conference back in October: