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.