Tethering a 3G smartphone to a laptop has the same effect as accessing the web via a 3G hotspot, albeit for only one PC. The function is built into iOS 4.0 and Android 2.2 Froyo or later.
Get online on a PC via your smartphone
In Android, select the Settings menu from the home screen and choose ‘Wireless & Networks’. Tick the box next to ‘Portable Wi-Fi hotspot’, then click ‘Portable Wi-Fi Hotspot settings’ to obtain the password.
Select your handset from the list of available wireless connections on the laptop. This can be accessed by clicking Start, All Programs, Control Panel, ‘Network and Internet’, ‘Network and Sharing Center’. Press Connect, then enter the password when prompted to do so.
On an iPhone, select the Settings menu from the home screen and choose General, Network. Click ‘Internet tethering’ to turn on the function.
Connect your handset to the laptop via Bluetooth or the bundled USB cable. Click the internet access icon in the System Tray, then select your handset from the list of available connections.
BlackBerry handsets also support tethering, although you’ll first need to pair the smartphone and laptop. Next, go to the Settings menu and choose ‘Internet tethering’. Note, though, that BlackBerry Enterprise handsets may preclude accessing the web this way. For details on how to pair a BlackBerry smartphone and Playbook tablet, see this knowledgebase article.