Enable tethering on your Palm Pre or Pixi with FreeTether
Once installed, you simply fire up FreeTether, select which interface(s) you want to enable, and configure its options. After that, all you've got to worry about is keeping an eye on your data usage so you don't get dinged by your carrier.
PreCentral reports that the tethered connection feels a bit slow at this point, but this is just the first release. webOS Internals has developed plenty of other great apps for the platform, so expect to see FreeTether improve dramatically in coming updates.
FreeTether is homebrew, so you'll need to make yourself familiar with how to install non-Catalog apps on your device via PreWare. It's a simple process, and there's no risk of bricking your phone -- so head on over to PreCentral for step-by-step instructions. You'll also need to add the testing feed to PreWare.