Some interesting links about design patterns in php with code examples

From fluffycat.com : abstract factory, builder, prototype, singleton, adapter, bridge, composite, decorator, facade, flyweight and many more ...

From sourcemaking.com : creational, structural, concurrency and behavioral patterns, with rules to make them, check-lists, ...

From ibm.com : factory, singleton, observer, chain of command, strategy

From ibm.com : adapter, iterator, decorator, delegate, state

From wikipedia.com : creational, structural, concurrency and behavioral patterns

And design patterns quick reference cards in pdf : from mcdonaldland.info