When trying to configure the latest binary of ghc (7.0.4) under Kubuntu 11.10, you might most probably get an error like: "libgmp.so.3: cannot open shared object file". You need libgmp3c2 installed before trying to configure ghc.
sudo apt-get install libgmp-dev libgmp3-dev libgmp3c2
Now you can do a
./configure.