Possible Clues:

• Smart ---, know-all
• Smart ___ (Var.)
• 'Ugly Betty' actor Mapa
• "30 Rock" guy
• Actor Guinness is smart
• Brother of Daniel, William and Stephen
• Eric Bedser's twin brother
• Guinness of "The Bridge on the River Kwai"
• Guinness of "The Lavender Hill Mob"
• He's Ben in "Star Wars"