We have covered HTC Hero Themes for iPhone and also HTC Pro theme for iPhone and now we have HTC Widget for the iPhone 4 and optimized for the retina display.
The theme brings in the exact look and feel of HTC theme on to your iPhone.

How to change the weather information:

To change your location, edit the Private\WeatherWidget\WeatherWidget.html  file in notepad. About half way down the file you’ll find the locale variable. Change it to your zip code.
To place on the lock screen, simply remove the ".disabled" from the end of the LockBackground.html file.

More details and download available here.