Trac seems to be the newest trend on project management stuff. It's basically a wiki engine, empowered with a bug tracking system, task manager (todo, etc), subversion interface (source code versioning control system so you can feel safe that your code is safe - if it's actually safe is another story), automatic timeline and possibly other stuff. You only need a server that can do Python cgi-binning, Clearsilver (says the docs), subversion (and it's python bindings) and possibly additional stuff. In other words, if you have a dedicated server or VPS (virtual private server, actually a dedicated-like thing, where you're the root, but in a virtualized environment with many others, where if you screw something up it doesn't affect them - in other words, a cheap way to have root access). For the latter, if you don't have much requirements, you may want to check out
VPSLink which offers cheapy VPS systems (i have one). Don't get the lower system, though, it doesn't have enough memory to run python and an sql server (i know from personal experience).