Pidgin-sipe is a bit of a PITA to compile on RHEL/CentOS. I read the README and attemted to yum the dependancies starting with a "yum groupinstall 'Development Tools'" Ensure the devel versions of everything are also included especially pidgin and then I hacked the configure script:
At line 11822 I ammended the current to read as:
pkg_cv_GLIB_CFLAGS=`$PKG_CONFIG --libs --cflags "glib-2.0" 2>/dev/null`
Ensure you have the right line first as line numbers might change with releases.
Compile and install! Ensure the plugins get stuffed in /usr/lib64/purple-2/ if your using a 64 bit install else pidgin won't find them.