I started to use color themes in VS.NET 2005 (after reading Hanselman post about it) and I really liked more dark color than default white. It is somehow easier for eye, imho.
Anyhooooow here are couple of links for pimping Visual Studio 2008. I found many intresting posts from Norwegian developers (I don’t know how I end up to click around Norwegian blog roll) Some intresing stuff I haven’t personally tried yet AnkhSVN – Adds Subversion Source Control Management features to Visual Studio. Open source / free.
Chech out more at Lars Wilhelmsen post Pimp my Visual Studio (2008) also this and this post is worth of checking out if you are intrested to see different apps that may help your daily coding/testing.