watir/watir-webdriver — pull request #270 by titusfortner (2014-09-11 00:03:13+00:00)
Title: Add previous and next sibling element methods

Blackbaud has been using these methods as part of its own fork of watir-webdriver (https://github.com/convio/watir-webdriver). I'm not sure what discussions have been had in the past regarding the differences between the repo's, but this seems like a good candidate for including in watir/watir-webdriver