If you're involved on managing large projects with customers that loves to have all "well planned", I'm sure that Microsoft Project is one of the tools you're familiar with.
Unfortunately, Microsoft Project has a big lack in my opinion: it doesn't come out with the Microsoft Office package, so you're forced to buy and install it separately. Not well...
If you need a software like MS Project but you don't want (or you can't) buy it, maybe you are happy to know that Projity has released the first beta of OpenProj, a desktop replacement for Microsoft Project. It is capable of sharing files with Microsoft Project and has very similar functionality (Gantt, PERT diagram, histogram, charts, reports, detailed usage), as well as tree views which aren't in MS Project.
The product seems really rich of features (and it's more "light" than Project). There's only a disadvantage (for me 
): OpenProj uses the Java Runtime Environment version 1.5 or later, so you're forced to install it on your machine.
When we'll see something lile this totally written in .NET (and publicly released)? When Microsoft will decide to integrate MS Project into the Office suite? 