In the quest to make our humble search engine the best it can be, we've implemented the OR operator in our search. So if you wanted to search for cats or dogs you can enter that as 'cats OR dogs'. If you want to do an OR between two exact phrases or an exact phrase and a single word, that should work too. For example 'cats OR "big dogs"' will work as you'd expect. Note that the OR must be capitalized for it to work.
This updated functionality should work in RSS, on the site, and in Twhirl. If you have any comments or suggestions, let us know at @tweetscan OR right here in a comment.