MiFi is the app we most wanted on my iPhone and overall one of the most useful. It is available through Rock Your Phone for $9.99.
What it does is simply turn your 3G iPhone into your own Wi-Fi hotspot. This is the functionality AT&T does not want you to have.
Once your iPhone is jailbroken through the Spirit jailbreak, go to Cydia and install MiFi. It is available only as a free trial through them. It will install Rock Your Phone, where you can purchase the full version through.
Once installed you open up the App and turn ‚ÄòWiFi tethering‚Äô on, that‚Äôs it. We do recommend enabling WEP security as well and giving your hotspot a password.
MiFi runs until you turn it off, and it is a power vampire so only use it when you have to or when it is plugged into a power source.
You‚Äôll be set to go and run that laptop‚Äôs Wi-Fi off your iPhone‚Äôs 3G, whilst on vacation without paying the hotel those Wi-Fi fees.