Maximizer is Lion's full-screen apps, but for every app. It adds support for Lion's full-screen to apps like Chrome and Firefox (which haven't yet been updated to support it) as well as ones like TextMate, which might never gain that support. It should work with any Cocoa app, but not Carbon ones.
To use Maximizer, you have to install SIMBL and then put Mazimizer.bundle inside ~/Library/Application Support/SIMBL/Plugins (or in the same folder in /, if you want it globally available). I probably can't help you get this installed; maybe read the SIMBL website if you get confused?