Use your iPhone as WiFi Hotspot
 

I know there is a tone of good apps for the iPhone but I give this particular a A++. MyWi is a cool and very useful iPhone app that enables to use your Iphone as a WiFi Hotspot to share the iPhone's internet connection with several computers. I installed MyWi on my new iPhone 3gs few days ago and have been using it since on the go and it worked perfectly. If you get a strong 3g signal the speed is very acceptable and it supports VPN. All of that for less than $10.
The only caveat is that the iPhone needs to be jailbroken to be able to install this app but the jailbreaking process is easy. Just wanted to share the info.
http://www.rockyourphone.com/index.php/mywi.html?feat=y

Does this app work for the 3G phone as well? or only 3GS?..couple more weeks it wont matter i guess. The Iphone 4G will be released. Meaning 4th Generation, not 4G network..thats a common misconception.

Yup it works on the 3G

One of my favorite apps, saved me $120 + a monthly fee by not needing a 3G iPad