I must confess that I'm rather liking Google's latest Universal Search capabilities. The Show options... feature was introduced in May of 2009. This feature simplifies the ability to narrow down your search criteria by launching an adjacent panel on the same screen. This panel allows you to hone results by result type (images, videos, etc), result time (24hrs, week, year, etc), and result views (more images, less text, timelines, etc).
I've found this to be a vast improvement over the previous method, which had you click a link that took you to a completely different page, and then prompted you to fill out an entire page of criteria prior to submitting your search.
Need more information? Check out the Google blogpost/video on the topic:
Official Google Blog: More Search Options and other updates from our Searchology event