RobertoAlicata

Usage:
write [qrcode] to generate a QRcode for the actual url with size of 100×100 pixels
you can specify these attributes:
size (it indicates the size in pixels for width and height, default: 100)
alt (it indicates the alternative text for the image: default “scan QR code”)
content (leave it blank to pass the actual url or write the content to encode)
click (write “yes” to make the image clickable)
fgcolor (foreground color in hexadecimal format)
bgcolor (background color in hexadecimal format)
example: [qrcode size=200 content=”www.robertoalicata.it” alt=”scan me NOW” click=”yes”]

ra_qrcode

a simple WordPress plugin to generate a QR code with a configurable shortcode and Widget

dweius

QutenizeR plugin for wordpress allows you to easily create personalized and colorful QR codes on the fly. <a href="http://qutenizer.com" title="qutenizer.com" rel="nofollow ugc">QutenizeR.com</a> is a free online Web service (beta) that generates full-color personalized QR codes on the fly. QutenizeR plugin for WordPress connects to it and get the images without leaving your blog’s admin pages. Feedback will be welcome. 
Enjoy this plugin!
This plugin uses Jan Odvárko’s JSColor available at http://jscolor.com

QutenizeR

QutenizeR plugin for WordPress is a funny way to easily create cute & colorful QR codes.

ra_qrcode vs QutenizeR