Yes, use the same search bar that you use for everything else, but you put in the name of whatever member you're looking for. A list of members whose names are similar to what you searched will appear on the right side of your screen.
You can also go to the Members page. There is a window that says Find Member. If you type the first 2 characters of a name, it will show players whose names start with those letters/underscores. http://www.sandlotminecraft.com/members/
This is most likely in the wrong place... But while you are playing minecraft on the Sandlot, the /find <player> command is useful.