walletool ~ a tool for reading wallet.dat files

Installation

Install Python 3.x.
Install the bsddb3 module (if you're on Windows, use Gohlke's site).

Extracting private keys from Bitcoin-QT/Litecoin-QT wallets

Have your wallet.dat handy.
For Bitcoin, run python wt_extract_keys.py -d wallet.dat -v 0
For Litecoin, run python wt_extract_keys.py -d wallet.dat -v 48

A list of addresses / private keys is printed.

YMMV :)