Turning your iPhone into a WiFi Hotspot is simple if you have a jail-broken iPhone. Your first FREE option is by PDANet. Unfortunately the FREE version gives you only HTTP however normally that’s ok. The Paid version gives you everything. The second option is MyWi. There is no Free version but for $9.99 1 time only, your iPhone will be a free Wifi Hotspot.
Android is simple and Free: Goto settings, Wireless & networks, Portable wifi hotspot.