Guess the plant!

Guess the plant!

I was given a plant today by a co-worker. She has no idea what it's called, no idea how to care for it (and, frankly, neither do I), only that it doesn't need a lot of water. Behind the cut are two rather large photos of this plant. I would be really grateful if someone could give me the name of the plant. I'd be happy to Google the rest. I've googled 'spiky flower' and 'spiky plant', but no luck. Photo Sharing and Video Hosting at Photobucket Photo Sharing and Video Hosting at Photobucket I appreciate the help! I am really new at this.
Hibiscus flower…

Hibiscus flower…

Balcony Container Garden: pic and a question.

Balcony Container Garden: pic and a question.

a “squeee!!!l look at my garden” post

a “squeee!!!l look at my garden” post

my grandfathers garden

my grandfathers garden

dining area help!

dining area help!

Mr. Hummingbird visiting my lantana

Mr. Hummingbird visiting my lantana