Bainternet

With This Plugin you Easily insert QR codes in your blog, with Widget or Shortcode. 
the plugin add a tinymce button so even the shortcode can be inserted for you.
Main features:
<ul>
<li>Very easy to use.</li>
<li>TinyMCE button for easy shortcode insertion.</li>
<li>built-in Widget.</li>
<li>Use as shortcode.</li>
<li>Use as template tag for easy integration with your theme or plugin.</li>
</ul>
any Feedback is Welcome.
check out my <a href="http://en.bainternet.info/category/plugins" rel="nofollow ugc">other plugins</a>

Simple QR Code

With This Plugin you Easily insert QR codes in your blog, with Widget or Shortcode.

This widget allow you to display your contact information (or other such as sms to, email to, note, MEcard and etc) in qr code form.
This widget works by displaying a qrcode which was defined by blogger to put contact information. Get qr contact information format from http://qrgenerator.mindster.net This web site allow you to generate most contact information format such as ME card,telephone number,url,wifi access code, send sms, send email and etc.

EasyQR

This plug in allow you to display your contact information (or other) in QR Code form.Just drag the widget into suitable location and you're done …

Simple QR Code vs EasyQR