Third party developers bent on creating applications for the iPhone, your attention please. The University of Washington's Emerging Technology group was able to take notes on Apple's "Developing Web Sites for iPhone" discussion taken from Worldwide Developer's Conference (WWDC), and since third party iPhone applications can only be web-based, it's good to take note of these guidelines.

Here is a list of what developers can tinker with to create iPhone applications:

• The page view feature lets you look at multiple websites and documents by scrolling through them one after another
• Full PDF support
• Double tap for zoom in
• One finger as a mouse used to pan page
• Press and hold to display the information bubble
• Two fingers as a mouse used to pinch content to shrink - zoom out
• Scroll wheel events
• New telephone links allows you to integrate phone calls directly from your web page. Only for Safari.
• Built in Google Maps client for integrated mapping from your website

However, there is also a set of limitations that should be taken into consideration:

• Separate HTML and CSS
  
• Use well structured and valid HTML
• Size images appropriately don't rely on browser scaling
• Tile small images in backgrounds, avoid using large background images
• iPhone supports both EDGE and WiFi. EDGE pipe is smaller than WIFI pipe so think about bandwidth when developing.
• XHTML mobile documents supported
• Stylesheet device width:480px
• Apply different css for the iPhone. For example displaying a one column page for iPhone vs. a 3-column page on a desktop
• There are no scroll bars or resize knobs. The iphone will automatically expand the content.
• Avoid framesets, scrollable frames are automatically expanded to fit the content
• iPhone User Agent: Mozilla/5.0 (iPhone; U; CPU like Mac OS X; en) AppleWebKit/420+ (KHTML, like Gecko) Version/3.0 Mobile/1A538a Safari/419.3
• Video: H.264 baseline profile level 3.0 up to 640-480 fps

They have also stated that the iPhone will not support Flash or Java applications, so there may be problems on running some websites. But some websites like YouTube are taking the initiative to help curb this problem by providing alternatives in accessing their content, like YouTube providing H.264 video specifically for the iPhone.

The no Flash and Java limitations may seem crippling at first glance, but this set of guidelines should help you on your way to building the best third-party program and/or game for the upcoming iPhone.