FIX: You are missing 32-bit libs: libGL.so.1

So I've been getting an error when trying to start Steam.

Luckily, I know how to use a search engine and quickly found a promising post by frankster. This did not fix my problems - I had to run this line to get Steam to work on my laptop:
sudo apt-get install libgl1-nvidia-glx:i386
Works like a charm. :)