Just a quick heads up for anyone installing Tesseract (Open Source OCR tool), the README does a great job explaining the dependencies and what you need to do to get up and running, but there is one little gotcha. After you run

$ sudo make install

You may still get an error when trying to run tesseract:

$ tesseract foo.png bar
tesseract: error while loading shared libraries: libtesseract_api.so.3 cannot open shared object file: No such file or directory

You need to update the cache for the runtime linker. The following should get you up and running:

$ sudo ldconfig