- Not super cheap, but pretty: Bento, from FileMaker: http://www.filemaker.com/products/bento/index.html ($50)
- Pretty cheap, not so pretty: Menial Base: http://menial.co.uk/software/base/ (£10)
- Free, fairly ugly, runs inside Firefox: SQLite Manager: https://addons.mozilla.org/en-US/firefox/addon/5817
Apparently they all use the wonderful SQLite, too.