Adding to the Selenium IDE’s already awesome “save your behind in every kind of situation possible” behavior, here is a plugin that adds the flow control constructs that are so sorely missed from the base language. This is a powerful, powerful addition that makes some horrible tasks… bearable.
Using Firebug to Evaluate XPath Queries in Firebug
Start the Firebug console and use the ‘$x’ function. It takes one argument, the xpath query in single quotes.