An article at PCWorld.com showcased several open-source projects that serve as alternatives to software products for which most users pay dearly. One of my favorites as an accountant was GNUCash. While I have not had time to thoroughly review the product, the screenshots appear similar to the registers in Quickbooks.
Considering the price of Quickbooks, and its lack of interoperability between versions (one of the greatest annoyances I have with the program) GNUCash may provide a very simple but powerful alternative for users that are familiar with accounting programs. I doubt that it is as pretty, but it seems to be a great value.
There were several other products shown in the review and it is a great article for small business owners who are tired of paying high prices for products that overpromise and underdeliver.