Avery, well-known for their labels and other office products, have released a design software package for Mac users called DesignPro. It doesn’t just do labels either but can be used for designing everything from labels to T-shirt transfers and greetings cards.
It is available for Leopard too and can import photos from iPhoto, as well as merge data from Mail and Address Book. All in all it looks like a capable package and for free its got to be worth a try. So, have downloaded it and I’ll be testing it out in the near future. I’ll post my thoughts at a later date. be warned though, its a hefty download at 262MB! So, unless you are on broadband, be prepared for it to take a while.