Marketcircle has a free, open-source Mac application, iPhony, that provides a pixel-accurate web browsing environment, powered by Safari, for developing web sites for the iPhone.

Here’s an example screen shot from iPhony browsing the New York Times. Note that the image shows up larger than life on your computer, because the iPhone’s display packs pixels together much tighter than typical computer screens:

If you want to test your blog or podcast site for compatibility with the iPhone, you may want to give iPhony a try. The app is a quick download, is easy-to-use, and has several features that should help with testing sites:

• A keyboard command lets you zoom in or out (no multi-touch, yet!).
• A keyboard command lets you rotate the screen.
• You can turn off plug-ins.
• You can specify a custom user agent string.

iPhoney is not an iPhone simulator, but is designed to help create and test 320 by 480 (or 480 by 320) websites for use with iPhone.