I've just found out that Qt 4.6 actually includes prebuilt LGPL binaries for Visual Studio 2008, so there's little reason to spend time building Qt unless you need to use some other version of Visual Studio.

The prebuilt binaries are downloadable from here. Alternatively, you can visit the Qt download page, choose LGPL, and look on the right hand side of the page for the download link.

I highly recommend using the prebuilt libraries, as you will save a tremendous amount of time (it takes hours to build Qt). After you finish downloading and installing the libraries, install the Visual Studio add-in to make it easier to handle the custom build steps for moc and ui files.