Geekbench (32 bit, try-out mode) won’t run out of the box on ubuntu 13.10 64 bit (or maybe also earlier versions). This is due to the removal of ia32-libs and switching to multiarch. Fortunately it’s easy to fix:
sudo apt-get install libc6:i386 libstdc++6:i386
This will install the required 32 bit libraries you’ll need to run geekbench in 32 bit mode.
Happy benchmarking!