Who's lizard is that on the fence?

I work for a "special district" and have the privilege of an office right on a canal that's flanked on the west by a pasture. The wildlife I have opportunity to observe is pretty impressive and it's my aim to share some of the photos I've taken around the office here on my blog. Which leads me to this photograph: who's lizard is that on the fence? He's not an iguana, for sure. And, I'm almost certain he's not native to Florida. Luke says its a Cuban Knight Nole. I looked it up on the internet, but only one picture I found looked like this guy. (Or, is it a girl?) He/she allowed me to get pretty close to take this shot, and, of course, the zoom lens helped. Note the yellowish tip of its tail and the rings around its eyes. If anyone knows for certain what lizard this is, I'd appreciate a posted comment. I often use these photos for the fourth and fifth grade students I teach about the Everglades and water conservation and I like to communicate accurate information. Today's weather is typical subtropical savannah on the last day of May: hot and humid with inland skies dark with coming rain. Good day!