This looks to be a brilliant application that allows you to managing you accounting very easily. As a small time contractor, this is the ideal application.

PHP Accounts 0.5.1 (Default branch) -
PHP Accounts is a simple and easy to use Web-based
client and accounts application of particular use
to freelancers or consultants. As well as basic
management of clients, income, and outgoings,
features include Generation of PDF invoices,
recording timesheets, CSV export, an invoice
wizard for quickly generating client invoices, and
automatic email reminders to clients for unpaid
invoices.

License: GNU General Public License (GPL)

Changes:
some changes have been added to increase compatibility with more environments. PHP 5 support was tested (slightly).

[FreshMeat]