Was just lurking around the net and found a few new Boxwave cases for the Nexus One.
This is a leather one that looks pretty unique:
Designio Leather Sleeve Case - Nexus One Leather Sleeve Case / Nexus One Leather Sleeve Case
Here are silicones that look like some other ones that have been out for a while:
FlexiSkin - Nexus One Case / Nexus One Case / Nexus One Skin Case / Nexus One Skin Case
A lot of them also offer free shipping.