You can never tell where this will lead you.

A note -- 2000 October -- most of these don't work too well, if at all; the Gopher/WAIS/Z-3950 protocols have been largely abandoned in favor of search-engines crawling FTP and HTTPD (web) space. However, it seems that a Second Generation Veronica might revive some interest in the lowly Gopher! Please see Veronica 2, which crawls most of the known remaining Gophers.

Government Gophers An excellent selection of government gophers.
Library of Congress MARVEL
Peripatetic Eclectic Gopher. This leads lots of places. Particularly take a look at the Virtual Reference Desk. If you can't find it from here, it probably isn't online.
InterNIC Gopher.
Listing of Molecular Biology (LIMB) Databases from the National Institute of Health's Division of Computer Research and Technology.