lwreg provides a flexible and easy to setup tool for registering the compounds used in a laboratory. The use of a layered hash for duplicate detection allows the system to store multiple variations (tautomers, stereoisomers, conformers, etc.) of the "same" compound, while still allowing very fast queries to retrieve related structures. We have also showed how the compound registration schema provided by lwreg can be augmented by additional tables, which are used to store experimental results, resulting in a lightweight system that can track metadata describing experiments (including computational experiments), the data from those experiments, and the compounds that were used in the experiments.