Mark Jaquith

This simple plugin (no configuration) redirects <code>?s=FOO</code> search URLs to the nicer <code>/search/FOO</code> versions. Requires pretty permalinks.

Nice Search

Redirects search URLs from ?s=FOO  to /search/foo and converts spaces to + symbols

Harsh Agrawal

Content syndication is a process of amplifying your content to other blogs without hurting the SEO of your original content. You can let other blogs to republish your content in exact format with rel=canonical tag.
You can read about Rel=canonical tag here at pt.4: https://support.google.com/webmasters/answer/139066?hl=en
In this guide you can learn everything about using content syndication for content marketing: http://www.shoutmeloud.com/relcanonical-wordpresss-content-syndication-seo.html
Canonical SEO Content syndication plugin adds a meta box at post editor section. You can add permalink of post where the content was originally published. Popular blogs like bufferblog, readwriteweb are taking advantage of content syndication and rel=canonical tags.

Canonical SEO Content Syndication WordPress Plugin

Canonical SEO Content syndication plugin adds rel=canonical tag for content syndication. The meta box is added at edit post section.

Nice Search vs Canonical SEO Content Syndication WordPress Plugin