A handy tip from the Bug Slayer MSDN column:
Tip 57 - To hasten the startup of the Visual Studio .NET IDE, get rid of the Start Page. Because the Start Page requires all Web-browsing components to be loaded, you can chop off a considerable amount of startup time by skipping it. To turn off the Start Page, select Options from the Tools menu to bring up the Options dialog. In the Environment/General property page, select "Show empty environment" in the "at Startup" combobox.
Of course, with Resharper installed, this causes the the IDE's start-up time to become terribly slow. But it's worth it!