Here are several news aggregators which I selected for you. Have a look and make your choice if you still have not done so:

Aggie is an open source news aggregator and a desktop application. It downloads the latest news and displays it in a Web page.

Awasu is a state-of-the-art feed reader that comes loaded with features for both casual personal use and professional, high-powered information management. It helps users to read their favorite blogs and news channel, to automatically download favourite podcasts, to integrate with blogging tools, to bookmark and annotate items, and more. Personal edition is free for download.

Bloglines is a personal news aggregator and is highly useful for teachers who want to stay on top of current events in any given topic.

BlogPulseis an automated trend discovery system for blogs, a blog search engine that also analyzes and reports on daily activity in the blogosphere. It contains also: buzz-tracking tools, blog trends, a conversation tracker for individual blogs, blogger profiles and more.

FeedReader is a free RSS news aggregation solution that offers advanced, cutting-edge capabilities, including the most comprehensive podcasting support available today.

GoogleReader constantly checks favorite news sites and blogs for new content.  It helps to share interesting items with others.

Popurls is an easy one-stop shop to follow internet buzz, and once registered you can personalise the site to show your favourite digital content sites first.

RssReader collect news in the background at user configurable intervals and warn with a little popup in the system tray that there is a new message arrived.

Syndirella is an open source desktop information aggregator - a program that provides a comfortable environment for reading the information coming from multiple sources, or feeds. The most common uses for Syndirella are reading news sites and weblogs.  It automatically notifies for news, news are in an  easy to read format, and can be kept as archive.

WikiNews: Anyone can contribute, and articles are written collaboratively for a global audience. They strive at all times to meet the policy of using neutral point of view, ensuring that their reporting is as fair as possible. Since this is a wiki, you can combine this site with other objectives in a project for your class.