While WordPress- and WordPress.com-sites are extremely consistent regarding their URI-structure, there's one big inconsistency. If some looks at:
http://wir-sprechen-online.com/tag/wordpress/
... and removes the "wordpress/" part he'll find himself at a blank page:
http://wir-sprechen-online.com/tag/
In my opinion he should find a *full* tag-cloud (all tags, not only the 45 of the widget) there. Just as he'd find all entries for June 1st, 2008 if he looks at:
http://wir-sprechen-online.com/2008/06/01/from-wordpress-to-social-media/
http://wir-sprechen-online.com/2008/06/01/
http://wir-sprechen-online.com/2008/06/
http://wir-sprechen-online.com/2008/
Your opinion?
Smile!
Gerrit