The most well known appearance of The Spirit in other media is probably the 1987 television movie starring Sam J. Jones ("Flash Gordon" in 1980) and Nana Visitor ("Kira Nerys" in Star Trek:Deep Space Nine). For further information about the film, click here. There was also a short film adaptation of the story "10 Minutes" in 1989 by Edgewood Motion Picture and VideoProduction which had adverts in the KSP Spirit reprint series.
However, The Spirit did also appear in a television series in 1948 - produced by Alan R. Cartoun Associates for a local Chicago television station, the series showed panels from the comic on the screen with vocal actors reading the speech balloons.
Jeff Rovin, in his 1985 "The Encyclopedia of Superheroes" lists in his entry for The Spirit a short-lived radio series written by Enid Hager although I can find no further information about this show.
In 1987, John Christensen released a picture disc of "Ev'ry Little Bug" which also included some sound clips from the 1948 television series - some sound clips from the series (as well as some other clips from the disc) are available to download below (the number of bytes and the length of the clips are also shown). The files have also been zipped to save download times - you will need a compression utility like Winzip to use them.
1948 Promo 1 - (881,382 bytes, 39 seconds) Promo for the 1948 television series. Also available as a zipped file (473,427 bytes) from here.
1948 Promo 2 - (356,476 bytes, 16 seconds) Another promo for the television series Also available as a zipped file (188,985 bytes) from here.
Ev'ry Little Bug 1 - (115,832 bytes, 5 seconds) Quick clip of one of the versions of the song from the 1987 album. Also available as a zipped file (63,898 bytes) from here.
Ev'ry Little Bug 2 - (209,552 bytes, 9 seconds) Another clip from the 1987 album, this time sung by 'Ellen Dolan'. Also available as a zipped file (96,929 bytes) from here.
In 1995, Byron Preiss Multimedia released The Spirit CD-ROM, which contained all of the sections for 1947. For more information, click here.