WordPress doesn’t have any Tagging solution by default. So you have to use a wordpress plugin to get the tagging functionality. WordPress codex provides a big list of plugin for tagging functionality. You will find it here. Some of the well known Tagging Plugins are UTW (Ultimate Tag Warrior), Jeromn’s Keyword.
But after some digging I have found something much simpler and effecient. It is Simple Tagging. First created by Michael and transferred to Amaury Balmer (Administrator of WordPress Franch). Now the Page for the plugin is here.
I liked everything about simpletagging plugin but one. It converts spaces between Tag phrases by a ‘-‘ hyphen. But the major Blog search engine Technorati expects spaces to be converted to ‘+’ sign. Technorati suggested in their Tag Help :
If your blog software doesn’t support categories or you’re not sure, you can still participate. To associate a post with a Technorati Tag all you have to do is tag your post by including a special link in the body of your post. Please note that two word tags should be joined by a “+”.
Actually simpletagging is a full powered Tag solution. It has its own search functionality it uses ‘+’ sign to mean addition of search tag. So it can’t use ‘+’ in place of space.