- Dead Tree: http://www.amazon.com/Design-Patterns-Ruby-Russ-Olsen/dp/0321490452
- Kindle: http://www.amazon.com/Design-Patterns-in-Ruby-ebook/dp/B0010SEN1S/ref=kinw_dp_ke?ie=UTF8&m=AG56TWVU5XWC2
- PDF and ePub: http://www.informit.com/store/product.aspx?isbn=0321490452
Reminder: if you're not sure about reading the whole book, you can probably get the Kindle sample on a device you own and read the first couple chapters along with us.