FeedWind - FeedWind is the world's leading RSS widget, Facebook widget and Google Calendar widget - works on any website and is fully customizable
Free Twitter RSS Feed Generator - Convert Twitter lists, hashtags & searches into RSS feeds
Feedly - The content you need to accelerate your research, marketing, and sales.
RSSMailer - Get your RSS feeds in your inbox 💌
Superfeedr - Real-time feed API - RSS and Atom over PubSubHubbub and XMPP. Superfeedr pushes RSS feeds in real-time for both publishers and subscribers, with open protocols and APIs.
FeedBlitz - FeedBlitz is a mega pack solution for social media marketing and RSS feed and subscriber integration.