I will not surprise you by saying that Facebook allows using iframes on fan pages and tabs. Anyway, there are, as usual, two major opinions on this matter. Negative one states FMBL apps are no longer accepted by Facebook, where another one is happily celebrating huge possibilities of creating own flash, php, javascript, etc applications and hosting them elsewhere. So I decided to try them on my end. I've spend few attempts to finally get it working (ouch..) and added my FlashMint flash template app to my Facebook page. It worked fine, and I have found some advantages so far. See them below: 1. My server is super fast, though my app loads really quickly; 2. Now my app can be as large (in size) as I want, and I can add as many media files to it as I want (such as videos, photos, audios....) which is pretty useful for socializing. I believe there are many other helpful features each of us can retrieve from this facebook feature. Let's stay connected and share the experience!
I use iframe on some of my facebook fan pages and find it more workable and handy that static fmbl. I can add videos straight to Facebook fan page and access my fan pages via my iphone as iframes are html5 compatible. I found the nice collection of facebook fan page iframe apps at hostfb.com, if someone may get interested.
Developers would prefer the iframe while the majority may find it a little bit more work to create an app. But it is actually more versatile and there are tons of tools / designers to help you
But new facebook timeline towards fanpages didn't allow us to develop our landing page. But we can add the iframe app as a tab in pages tab area. But as before we can't set it as a landing page.