Here's a roundup of beer-related homemade tools on HomemadeTools.net.
There are essentially three categories of beer-based homemade tools:
1. Tools used for brewing beer.
2. Tools made from beer brewing tools.
3. Tools made to convert beer brewing tools into other tools (just the Keg Lathe).
Most of these make use of beer kegs, a really useful common tool ingredient. Broadly, the kegs get used as containers - usually tanks, occasionally furnaces, and in one situation, as a rotated fish scaler.
Here they are: