If you take a walk over to http://www.pinvoke.net, you can find an active WiKi community that is documenting the PInvoke statements used to call Win32 and other unmanaged APIs from managed code. While you're there, why not add signatures and other information for any of the unmanaged APIs you've recently called? Adam Nathan, who created the WiKi site, also has contributed a PInvoke.Net Visual Studio add-in that's available on GotDotNet.