Icon design can definitely be considered as a contemporary artform, and finding a nice-looking collection of icons certainly is no easy task. For the Office 2.0 Setup, I used one from Jakub Steiner, who might be one of the most prolific — and certainly one of the most talented — icon designers today. His work in progress page is a very good place to start from. An other one to look at is IconBuffet, which provides a very nice collection of royalty-free icons for use in commercial and personal products. Pricing is affordable, design is clean, and collections are comprehensive. The people behind IconBuffet also have a nice blog and recently posted a great article on Bitmap vs Vector for icon design. Have fun using them for your Office 2.0 applications!