The BDP RSS Aggregator captures RSS feeds for the sites you select and displays them on your web site. It does this without using cron. Instead, every time someone visits your site, that hit is used to poll the most out of date feed on your feed list. The Aggregator is fully configurable from the WordPress dashboard.
An example of the Aggregator at work can be seen here.
Alpha version 0.3.0 was released on Friday 21 July 2006. The plugin is here. This version has been updated to use MagpieRSS that comes with WordPress. It now allows for automatic fractional GMT adjustments. There is additional information on the control panels, including the age of the most recent post from each feed. Links can be launched in new windows. Feed names can be permanently changed.