Coin software

Found this post on the benefits of using software packages for managing one's coin collection. As a computer programmer by trade, I tend to design my own software... but never seem to get around to implementing it :( At the moment, I am doing my best to keep the relevant data about my acquisitions in a Google Docs spreadsheet that I can access from home or elsewhere, and theoretically could take with me in my Sharp Zaurus palmtop computer to coin shows and stores.