Bird watching - Feed them fresh fruit - Baltimore Orioles love oranges and Cardinals love grapes. Orioles love grape jelly too and if you put out either one, woodpeckers really like them too. Butterflies like them too.
A Bower bird's nest. Sculpted just so, scattered with found items, collected to impress females. "Look at all these things I found, care to mate?" Bower birds are artists as each nest is different and each bird decides which items are worth collecting.
Looking for hummingbird nests? They're small and often hidden, but this image by Bill Hilton Jr.via Operation Ruby Throat will give you an idea of what to look for. Do not remove any nests you find because hummers and other birds reuse their nests.