Better tracking of development projects
I decided to use bugzilla, a well known bug-tracking tool that has a rich feature list, like database back-end, security, search cache, e-mail support and many more.
With bugzilla it is easy for me to list bugs and unwanted features, problems my customers have and other quirks. With an intuitive interface, a priority list and with e-mail support it's really easy to improve my development.
Another smart tool is trac, an integrated SCM & Project Management tool. This is besides an issue tracker, also a wiki and a web based subversion repository. But since it has too many features, I stick to bugzilla.