Google Reader is a handy tool - similar to Netvibes which I also use. Its basically a filter for the parameters you set it up to search for. You can create lists searching for keywords or websites and any new information will be diverted into your lists for you to read at your leisure. It saves time by giving you the things you want rather than you having to trawl your favourite sites looking for new content.
Google Reader is a Web-based aggregator, capable of reading Atom and RSS feeds online or offline. It was released by Google through Google Labs.
One of those handy use of Google Reader for SEO purpose is to set-up a Google Alert which alerting for new blog post in your niche then put the RSS of the Alert on the Google Reader. This way, you will be notified if there's new post from other blogs in your niche and hopefully you'll be able to post your comment there.
Google Reader is actually a feed reader which allows you to retrieve updates sourced from blogs and news sites you are interested in. Google Reader was launched in tandem with Google Gears. If you successfully installed Google Gears, you may download 2,000 updated items these may be viewed later when you lack Internet access. If you are interested in Google Reader, you may start using it when you click on the offline link located at the upper right corner of Google Reader. RSS feeds downloaded into Google Reader may be viewed through devices which allow you to do so even offline.