Description:
RSSOwl is a free and powerful news feed reader. RSSOwl lets you gather, organize and search news in a convenient, easy to use interface with endless flexibility.

RSSOwl can be used on all major platforms like Windows, Linux (32 Bit and 64 Bit) and Apple Mac OS X.

What is RSSOwl?
Applications that collect data from RSS-compliant sites are called RSS readers or "aggregators." RSSOwl is such an application. RSSOwl lets you gather, organize, update, and store information from any compliant source in a convenient, easy to use interface, save selected information in various formats for offline viewing and sharing, and much more. It's easy to configure and the best of all: It's platform-independent.

http://www.rssowl.org/overview

Author's website
http://www.rssowl.org/

I saw the features on the Author's website. Seems quite powerful and interesting. Looks like a portable (ZIP) version is available for download - will check.

Although it needs Java!! as mentioned in the download page.

NOTE: Make sure to have a working copy of the Java Runtime Environment (JRE), preferably 1.5.x or 1.6.x installed.

Oh!! its 14.3 MB download....