1. Download and install File Expert (click here to read full review)
2. Launch File Expert and tap ‘share’ at the bottom
3. Select ‘Enable Web Sharing’
4. IP and Authentication info will be displayed.
5. Note down the unique url (http://192….), username and password because it will be required later on for logging in!
6. Go to browser on other device (iOS, Blackberry, Windows Phone 7) and enter the unique url.
7. After entering the credentials, directory contents will appear in your browser of your device including SD Card.
Its that simple. This was successfully tested on devices such as Nexus S, and iPhone 4. Though it might not work on some devices depending on there protocols and authentication settings.