iPhone Applications

Hi, I want an application for iPhone / Blackberry / Hand-held devices which will allow the user to login her / his account. Based on user identity the application will display content to user and will allow the user to guide thru various mobile-web pages. The user details will be maintained in database. The user will have access to similar content on internet too (which already exists). The main idea of this task is to enhance the user experience - i.e. allowing the user to access the contents of her / his account from mobile device. PLEASE GIVE A ROUGH ESTIMATE ON QUOTE (You can mention on average how long it takes to develop iPhone apps and whats the pricing involved) Do feel free to recommend the technology and your past work. -ANaP