ScottGu's Blog contains a great article on managing your web projects. Check it out.

I've seen several questions come up in the last few days regarding techniques for structuring project layouts with web projects in VS 2005. In particular, I've received several good questions asking for ways to manage large image directories as well as temporary storage directories underneath web project roots. One goal with both questions has been to find ways to avoid these files from showing up in the VS web project solution explorer and cluttering up the web project view, as well as to avoid having these files/directories be prompted to be added to source control during check-in (note: you can just unclick having these files added to source control – but having to-do so can be a pain).