Best Free Add-Ins for Internet Explorer

I just found a post which describes best Free IE Add-Ins, some of them are really cool, I wonder why I didn’t know some of them yet. anyways here is the list:

IE7Pro
Website: http://www.ie7pro.com/

Quero
Website: http://www.quero.at/

Feeds Plus
Website: http://www.enhanceie.com/ie/feedsplus.asp

Inline Search
Website: http://www.ieforge.com/InlineSearch/HomePage

IE7 Open Last Closed Tab
Website: http://www.muvextoe.com/download.php#ieolct

GooglePreviewIE
Website: http://ackroyd.de/googlepreview-ie/

ieSpell
Website: http://www.iespell.com/

StumbleUpon
Website: http://www.stumbleupon.com/

del.icio.us
Website: http://del.icio.us/help/ie/extension

SiteAdvisor for Internet Explorer
Website: http://us.mcafee.com/root/product.asp?productid=sa&brw=ie&affid=0