Google just rolled out a search autocomplete feature for Gmail; If you turn on “Search Autocomplete” from the Labs tab under Gmail Settings, you’ll get suggestions in your search box while you are typing like you do in Google’s search box.
The search feature is pretty easy to use and definitely helpful. If you are looking for a contact, you can just type a couple letters of the person’s first or last name and the feature will provide a list that matches the search query. Google has added some advanced features like the ability to search in specific places (e.g. in chats or sent items), or search for messages with attachments by certain type (e.g. docs or photos). But finding that email from six months ago among the tens of thousands in your archive just got easier.