Forget what Steve Jobs says about not tethering your iPhone and iPad, you can do it easily!
Note: this requires a jailbroken iPhone. There are plenty of references out there that provide instructions on jailbreaking your iPhone if you don't already know how.
Here's a set of steps and images describing how you can tether your iPad and iPhone. The process is quick and easy, will take just minutes, and will cost you only $9.99 ONCE as opposed to $30 a month for 3G access on your iPad.
1) Launch Cydia on your iPhone
2) Navigate to the System program group
3) Select MyWi (no Rock) to install
4) Click the purchase MyWi button
5) Once you've successfully purchased MyWi and completed installation, launch MyWi on your iPhone and click authenticate to verify you've purchased MyWi.
6) Agree to carrier charges warning.
7) Name your Wireless hotspot
8) Configure your security and WEP key settings and choose a WiFi channel if you like. Also, I recommend turning off USB and Bluetooth tethering if you're not also using this hotspot via PC.
9) Connect to your new hot spot via your iPad!
Tutorial images via iclarified.
Enjoy!
