[OFFICIAL] Samsung Galaxy 3 GT-i5800 (root, gps fix, upgrading) - Page 78 - xda-developers: "To those who already have rooted their mobile,enabled live wallpaper still need internet via ad-hoc(from laptop)
extract wpa_supplicant in root.zip from rmagyar's post
people who need their mobile to use internet from laptop replace the wpa_supplicant file using root explorer in system/bin folder restart your mobile.now that it can see ad-hoc network but couldnt connect to it,struck in obtaining address thing....
First Configure it as a computer-to-computer (ad hoc) wireless connection, then press add in the wireless network window. Specify a network name (SSID) in the wireless network properties window and set it as open. If you want encryption for your wireless net work, please choose WEP and enter a pass key.Then clicks advanced and choose Ad-hoc for your WLAN network mode, and finish it. Please note you should enter the same SSID when you configure your mobile, or you will not be able to connect to the laptop.
Second, Configure your Wi-Fi mobile phone. In wifi settings add new wifi,enter a name and enter your SSID as your WLAN network name. Please note if your wireless network is open, you should choose open network for the WLAN security mode, otherwise you have to enter your WEP key as you entered above.
When this has been finished, go to the advanced settings. Choose IPv4 settings, specify the IP address as 192.168.0.3 or others other than your modem's ip and laptop's ip. And enter ip of your laptop as the default gateway. Now click on start, and choose RUN, enter CMD and click ok. Enter ipconfig/all when a CMD window appears, wirte down the primary and secondary DNS addresses of the network that connect to the internet. Now enter these DNS address in your mobiles IPv4 settings.
Third, Configure ICS. Right click on the Local Network or any network that connect you to the Internet, select properties and then advanced. Enable Internet connection sharing (ICS) and choose your WLAN network.Just confirm and finish it. Then your mobile phone will be able to connect to the Internet through your laptop.