Tools/gems for A/B testing

Hi guys,

What tools/gems(paid of free) do you use for A/B testing in your rails 3 applications? I have looked at Google's Web Toolkit, but it diverts heavily from the DRY methodology, I have tried both the abingo and vanity gems, but they don't seem to support Rails 3. Are there any others out there that are used? Has anyone been able to use vanity successfully in a Rails 3 app?

Thanks and Regards.