I forgot to announce it a couple of weeks ago, but FoFRedux, a web-based RSS aggregator I help lead and develop released version 0.3.
The version itself brings lots of little changes, including tagging, better categories, PostgreSQL DB support, and beginning mapping output . But most importantly it added RSS output. Many RSS "Readers" state that they are "Aggregators" when that's not the case. FoFRedux is an aggregator that can mix feeds that you subscribe to, and output them by category, tag, or search criteria. The next version will add better and more advanced search capabilities and RSS output in various flavorings, including consuming and producing GeoRSS.
But perhaps the biggest change to the next version of FoFRedux is the excellent UI redesign being headed up by Khaled of Broken Kode. The most common complaint of FoFRedux has been it's UI when compared to desktop readers or online readers. Well, that's going to change. Check out the UI redesign page to see the current mock-ups.
If you have any desired features or ideas for an online aggregator, chime in now!