First, thanks dejal for creating this. It's a great piece of freeware.
One change that would make it even more useful for anyone who, like me, uses this to stop them from wasting time would be a variant that only froze certain programs. If that existed, I could shut down firefox or a game, but keep word or excel open. And that would be great.
Re: Selective time out (internet, etc...)
A few years ago I had a similar idea, of watching what applications you're using and helping you restrict usage of non-productive ones. I wrote up a description of a product I code-named "Discipline". I am thinking about adding such features in a future version of Time Out, though probably not in version 2.0.
As far as Firefox is
As far as Firefox is concerned, you can download an add-on that allows you to selectively block yourself out of certain sites (that you specify). I don't remember the name of the add-on (I don't have it, though I probably should), but it allows for two great features. First, you can specify delayed blocking (it will block you after ten minutes of use; allowing access to quick info but hindering getting lost in distraction). Second, you can specify effective time ranges (it will only block you between 9am-5pm, for example). You can also combine these, such that it only blocks you between 9-5 and after ten minutes of use. A quick search should bring it up.