I have a rooted Precedent. I only tether with a usb cable. PdaNet was easy to setup and use.

PdaNet also says it works with Bluetooth. The PdaNet ad says that a phone does not need to be rooted to work.
Here is what I did. Downloaded free PdaNet 3.02 from the market. Installed free PdaNet drivers on Windows computer (need the drivers to tether).
When you need to tether via USB, first set the phone to debug mode. Easy to do. Here is the path: home > settings > applications > development - then click on "USB debugging" so the green check mark comes up in the USB debugging box. Don't forget to uncheck (turn off) USB debugging after your tethering session is completed.
Start the PdaNet app on your phone. After the app opens, click "Enable USB Tether." (If you forgot to turn on USB debugging, the app will tell you to do it.)
After connecting the USB cable to your phone, PdaNet will pop up on your computer (shortcut on task bar of Windows) and connect to your phone Internet network. (If for some reason, PdaNet does pop up a window saying it is connected, just click on the PdaNet shortcut on the computer task bar and click on "connect.")
Then you can surf the net, check your e-mail, etc. It is not complicated, but I went into a lot of detail just in case you are new to Android.
The one important drawback to using the free PdaNet rather than the paid Pro version, is the free PdaNet will not allow you to connect to secure web sites (Google Mail, Android Market, etc.). After trying PdaNet for a week, I bought the Pro version which is $15.95 and includes permanent updates. Don't freak out at the price there are other less expensive options.
I only occasionally need to tether. It is work related when I do and I need to access a secure web site. It was easier for me to just pay the $16 bucks and get my work done than to take the time to find a cheaper alternative.
There are a bunch other tethering apps on the market which cost less and may work very well for you. You might want to play around with the free PdaNet version and then try some of the other tethering apps to find the cheapest workable option for you.
Please give me a thanks, if this helped.
