On Tuesday Yahoo introduced two new search iPhone applications at the C.T.I.A. conference in Las Vegas.

One of the apps, called Yahoo Search iPhone App, is an integrated search service for the Apple iPhone and includes a number of interesting features, including voice search and “Shake to Clear,” which does exactly what the name describes: clears the last search when you shake the phone.

The new app also offers a range of new local tools and features  that can refine a Yahoo search based on a user’s current location and also add relevant maps using location-aware technology.

The other new iPhone application is called Yahoo Sketch-a-Search.

The service works by allowing users to draw a boundary on a map around a specific location. The app will then bring up local content, including restaurants and businesses, without a user needing to know the name of an area or neighborhood. In addition, the app also filters restaurant results by cuisine, ambiance and star rating, Yahoo said.

The release of these new applications and other recent mobile content shows Yahoo’s continued efforts to stay involved in the growing mobile space.

In the early days of the Internet on cellphones, Yahoo was considered a thought leader, releasing numerous mobile applications around news, search, mail, and chat. Over the last several years, Yahoo’s competitors have quickly surpassed the company by releasing handsets, operating systems and entire ecosystems around devices.

Opera Software on Tuesday announced that it is submitting its Opera Mini Web browser to Apple for use on the iPhone.

The Norwegian company boasts that Opera is the most-used browser on mobile devices; it offers a version of the software for Windows Mobile phones, Google Android and the Nintendo DS game system.

The Opera team said they are confident their new browser will be approved for the iPhone, but the final say is still up to the gatekeepers at Apple who are known to block applications in the iTunes store for any number of random reasons.

Last week I had a chance to sit down with Opera’s co-founder, Jon Stephenson von Tetzchner, to see an early version of the new iPhone software. The new browser loaded pages extremely quickly, as you can see in the video below, and manages to integrate some unique features that are currently available in its desktop browser. Some of the highlights include unlimited tabbed browsing and the ability to search the content of a Web page — an important feature that is currently unavailable on the Safari mobile browser made by Apple.

The software was missing an important feature on the iPhone: the ability to resize a page by pinching a page with both fingers.  Mr. Tetzchner said this could be added to the software with a later update.

The Opera browser loads Web pages rapidly by using a technology called server-side rendering, which compresses most aspects of a Web site on a server, sometimes reducing the load time of 90 percent of a Web page, before sending the data along to a phone’s browser.

Mr. Tetzchner pitched the new Opera browser as a way to reduce roaming charges when traveling.

Opera Software says its mission is to make a browser for any computer and mobile phone.