Firefox 3.6 has some interesting featureset

Firefox 3.6 Beta 1 have some really interesting set of new features. Read this page for the full feature list, I have reproduced an excerpt that I found interesting:

DOM

Drag and drop now supports files

The DataTransfer object provided to drag listeners now includes a list of files that were dragged.

Detecting device orientation

Content can now detect the orientation of the device if it has a supported accelerometer, using the MozOrientation event; see window.onmozorientation for details. Firefox 3.6 supports the accelerometer in Mac laptops.

For XUL and add-on developers

If you're an extension developer, you should start by reading Updating extensions for Firefox 3.6, which offers a helpful overview of what changes may affect your extension. Plug-in developers should read Updating plug-ins for Firefox 3.6.

New features

Detecting device orientation

Content can now detect the orientation of the device if it has a supported accelerometer, using the MozOrientation event; see window.onmozorientation for details. Firefox 3.6 supports the accelerometer in Mac laptops.

Monitoring HTTP activity

You can now monitor HTTP transactions to observe requests and responses in real time.