libcurl is the most featured and thus too heavy for Pacman, IMHO. I don't know if compiling it with some featuress omitted will help much. A list of libraries can be found at http://curl.haxx.se/libcurl/competitors.html
Exactly. curl is too heavy for this.
libfetch seems to be nice alternative to ftplib. It is small, has simple and stable API, is maintained, supports HTTP and FTP downloads and uploads, HTTP proxies and redirects. Sources are here: http://www.freebsd.org/cgi/cvsweb.cgi/src/lib/libfetch/
Yes as i see. Its great and simple. And it supports file:/// too! Which is not bad. Since as i know pacman now got "own" routin for handling those types. I support libfetch! :) Vote for libfetch! libfetch for President! :) (sorry :) ) Regards -krix-