In Ubuntu 13.10 (Saucy Salamander), it seems that the libturbojpeg .so filename has changed from libturbojpeg.so to libturbojpeg.so.0 and this breaks Bumblebee. Below you'll find a quick fix for this issue.
On my Ubuntu 13.10 laptop I got the following error when trying to run "optirun":
"error while loading shared libraries: libturbojpeg.so: cannot open shared object file: No such file or directory"
If this occurs on your Ubuntu 13.10 Saucy Salamander laptop, fix it by using the following command:
sudo ln -s /usr/lib/i386-linux-gnu/libturbojpeg.so.0 /usr/lib/i386-linux-gnu/libturbojpeg.so
sudo ln -s /usr/lib/x86_64-linux-gnu/libturbojpeg.so.0 /usr/lib/x86_64-linux-gnu/libturbojpeg.so
Bumblebee should then work:
via Bumblebee @ GitHub