How can I determine the latest released firmware for my Samsung device? This problem eludes me. I have two Samsung Android devices, a Galaxy Tab 10.1 and a Galaxy S2. I keep'em up-to-date using the update option in the settings panel, however, I think I'm not always sporting the newest firmware that was released, maybe because of region issues or some other reason. 

So I would like to know if there's a Samsung website or any other source where I can spot the latest stock firmware available?

Thanks all
In general there really doesn't seem to be a good way to keep up with updates that haven't been released directly to you.  I find the best way is simply to be involved in the "Android ecosystem" &mdash; reading Android blogs and news sites, and so on.

Sometimes there are stock ROM lists maintained on sites like XDA, for example this one for the i9001, and you can monitor those.

For actually acquiring ROMs, see: Where can I find stock or custom ROMs for my Android device?