When you are looking at a folder in Vista with Windows Explorer, you can set your configuration so that all you need to do to search the directory is to start typing your search string. To set your configuration this way, go to the Control Panel and select Folder Options and then click on the View tab. Scroll to the bottom to the setting called Automatically type into the Search Box and check the box next to this then save your changes.

Once you set things up like this, when you are looking at a folder all you have to do is start typing and it'll start searching the folder for what you are entering.