@chromalchemy: here's an exurb from one of my applications:

(def fonts [(font "avenir"    :normal :300 ["Avenir LT Std 45 Book"]   ["avenir-lts-std-book.ttf"])
            (font "avenir"    :normal :500 ["Avenir LT Std 65 Medium"] ["avenir-lts-std-medium.otf"])
            (font "geometos"  :normal :500 ["Geometos"]                ["geometos.ttf"])
            (font "futura"    :normal :500 ["Futura ICG"]              ["futura-icg.ttf"])
            (font "futura"    :normal :700 ["Futura Heavy"]            ["futura-heavy.ttf"])
            (font "futura"    :normal :300 ["Futura Light"]            ["futura-light.ttf"])
            (font "kaushan"   :normal :500 ["Kaushan Script"]          ["kaushan-script-regular.otf"])
            (font "core-sans" :normal :500 ["Core Sans G45"]           ["core-sans-g45-regular.otf"])
            (font "sfns"      :normal :500 ["SFNS Display"]            ["system-san-francisco-display-regular.ttf"])])

(window :fonts fonts ... )