Martha Stewart's "Eyeball Highball"
From Martha Stewart!:
Trim the stem and root ends of a radish (make sure its small enough to fit the individual section of an ice-cube tray), and use a paring knife to scrape off most of the red skin. Leave just enough red to give the radish a veined appearance. Rinse the radish off, and use a small melon baller to cut 1/2-inch-diameter hole into the radish. Fit an olive, cut side out, into the hole, and place the radish in the ice-cube tray. Repeat this process until the tray is full, then pour water over the eyeballs, and freeze.