There's a link to download the source, too. Source is for version 2.5.2, and the filename is pidgin-2.5.2.tar.bz2. Assuming that file has been downloaded to your home folder:
cd ~
ls
tar jxf pidgin*
cd pidgin*
./configure
make
make install
The "C compiler cannot create executables" error comes with a line number. You didn't happen to write that down, did you? If not, run it again. Pretty sure that has to do with an autoconf versioning problem, since that's where the error message appears in the code, but it could be something else.
In case anyone's interested, I could not install this on my Mac because I don't have glib installed.