I'm presently working on a BugTracking tool that I began working on here in July. I'm writing it in PHP with a MySql backend. All is going well with both technologies, I think PHP & MySql is a good fit for a BugTracking tool. Both technologies are truely multiplatform and free.
I'll post updates of my progress in the future. I need some help in the graphics area if your interested in helping me feel free to email me.