by Anthony Long.

Wait for one of two conditions to happens before continuing.
    wait_for_either("//*[contains(@class, 'foo-empty')]", "//*[contains(@class, 'foo-full')]")

Block until the count of an xpath query returns a specific number.
        wait_for_xpath_count(xpath, number, [wait_time=60]).

Switch to any other active session.
Intelligently kill other sessions, will not end current session if another session ID is specified.
        New commands:
                get_current_session_id
                get_active_session_ids
                switch_to_session
                kill_session

Create an 'on_error' method, that will be ran whenever you encounter a failure.
        New command:
                selenium.on_error = your_func

Add headers, and view your current headers.
        New commands:
                add_headers
                view_headers

True implicit waits for all functions that take a locator.
        New commands:
                This is done automatically for you.

Wait for things to happen with:
        wait_for_element
        wait_for_element_to_disappear
        wait_until
        wait_for_attribute
        wait_for_attribute_to_disappear

1: Built in, intelligent support for javascript libraries such as Moo Tools, Prototype and more. 2: Better methods for validating attributes.