If you’ve found yourself stuck in Chromes full screen mode, you’re not alone. Chrome has it’s benefits, like syncing and the native omnibar, but unfortunately Chrome does not play well with Full Screen Mode under– at all. You are free to click the full screen button to get in, but trying to escape from it can be a fruitless endeavor, with the menubar inconsistently appearing or not appearing at all.
If you’re stuck in full screen, hit Command+Shift+F to escape. This is the only guaranteed way to escape, although you can try, often fruitlessly, to poke around in the area of the menu bar hoping it will appear so you can access the exit function from the View menu (see screenshot).
The word is that Chrome will get native true full screen support soon, but until then you can try using Maximizer which works across all apps. And just be sure to remember that keyboard shortcut, it’ll save you a headache or two.
Update: The latest Chrome Canary build includes Full Screen support for OS X Lion, although it behaves slightly differently than normal full screen mode.