TwitterSearch is a handy Twitter extension for the Opera web browser. It combines search with notifications, which makes it a powerful extension for Twitter users, and those who monitor Twitter for news.

The extension adds a single button to the Opera address bar. A click on the button triggers the search form. Just enter a search term into the form and hit the enter key afterwards to search Twitter for that phrase.

The latest hits are displayed right in the same interface, no need to go to Twitter or another page to read the tweets. Links are directly displayed so that they can be followed directly without having to load the message on Twitter or another website.

The Opera extension does not update the search results automatically. A small slider beneath the search form determines if the extension checks for new tweets automatically. Available intervals range from every five minutes to every three hours.

The new message count is then displayed directly on the extension’s icon in the Opera address bar. Opera needs to remain open for that, but the Twitter search window can be closed.

What I really like is the fact that you can interact with the tweets directly. But it is not only the messages that you can interact with. If you click on an author’s name, you see all the tweets of that Twitter user in the search results window.

If you know the name you can use the from:name search parameter to directly display tweets from that user.

What’s missing? An option to monitor multiple phrases would be nice. There is also no back button to go back a page, for instance if you clicked on a username in the interface.

Opera users can installer TwitterSearch for Opera directly from the Opera extensions repository.

If you run Opera you can use the Widgets menu to Add Widgets which will load the Opera Widgets website as well. The main difference between Firefox add-ons and Opera widgets is the fact that Opera widgets run outside of the browser as separate windows which is sometimes a blessing and sometimes an annoyance. Take the Google Toolbar widget for Opera for instance. It runs independently of Opera which means that you can use it even if Opera is minimized. But, if you position it and make it stay on top and change the window size of Opera it will be in front of other elements on your desktop that you might need.

It’s great for all kinds of things but not that great if you want to integrate an element in Opera directly. Say you want to check the Google Pagerank of a website. Firefox simply adds the information in the status bar, in Opera you have your own window floating around that is either always on top – which does mean that it will still be on top if you minimize Opera, or hidden behind new windows that get opened.

I’m not an Opera expert and it would be great if someone else could tell me if there was a way to integrate widgets directly into Opera. Or if there were some sort of add-ons that could be integrated into Opera.