Dennis

The QR Code Tag plugin creates QRCodes for your blog.
Features:
<ul>
<li>Choose your QR Code generator: Google Chart API (online connection required) or QR Code Lib (included)</li>
<li>Uses cURL if <code>allow_url_fopen</code> is disabled (Google Chart API) </li>
<li>GIF, PNG or JPEG image output</li>
<li>All QR Code images are cached</li>
<li>Use as a Sidebar Widget</li>
<li>Use the Shortcode <code>[qrcodetag]content[/qrcodetag]</code> within your posts</li>
<li>Use the Tooltip mode <code>[qrcodetag tooltip="content"]some text[/qrcodetag]</code> within your posts</li>
<li>Use the PHP function inside your own template</li>
<li>“Best Read Mode” for optimized QR Code image size</li>
<li>Works with PHP 5.3 as well</li>
<li>Works on symlinked plugin folders</li>
<li>Available plugin admin interface languages: English, German</li>
</ul>
<h3>Demo</h3>
See <a href="http://www.spreendigital.de/blog/2009/09/18/essential-android-applications/" rel="nofollow ugc">this blog entry</a> for a tooltip mode demo. 
Move your mouse over the application links.
<h3>Acknowledgements</h3>
This WordPress QR Code Tag Plugin is partly based on <a href="https://wordpress.org/extend/plugins/super-cool-qrcode/" rel="ugc">Super Cool QRCode Widget</a> by <a href="http://www.incerteza.org/blog/" rel="nofollow ugc">Matias S.</a>.
It uses:
<ul>
<li><a href="http://code.google.com/intl/de/apis/chart/" rel="nofollow ugc">Google Chart API</a> for online code creation</li>
<li>Y. Swetakes <a href="http://www.swetake.com/qr/index-e.html" rel="nofollow ugc">QR Code Library</a> for code offline creation</li>
<li>J. Zaefferers <a href="http://docs.jquery.com/Plugins/Tooltip" rel="nofollow ugc">jQuery Tooltip Plugin</a></li>
</ul>

QR Code Tag

Uncaught TypeError: $(...).tooltip is not a function

creates lots of errors with new wp

Use QR Codes (Google API or QR Code Lib) anywhere in your blog, as a Widget, Shortcode, Tooltip or with a PHP function.

cballou

PHPull is a WordPress plugin for developers who wish to easily and accurately reference php functions directly from the PHP.net website. The plugin is very easy to use and the tooltip display is easily customizable by updating an existing stylesheet theme or creating your own. More detailed information and examples can be found on the official plugin homepage, linked below.
Credit goes out to S.C. Chen for his Simple HTML DOM class that was used in this plugin. For more information on this class, please visit http://sourceforge.net/projects/simplehtmldom/.
Credit also goes out to Michael Leigeber for his amazingly lightweight tooltip javascript code. For more information on this class, please visit http://www.leigeber.com/2008/06/javascript-tooltip/. Michael also has a wonderful blog.
Related Links:
<ul>
<li><a href="http://www.jqueryin.com/projects/phpull/" title="PHPull WordPress Plugin" rel="nofollow ugc">Official Plugin Homepage</a></li>
<li><a href="http://github.com/jqueryin/PHPull/archives/master" rel="nofollow ugc">PHPull on Github</a></li>
<li><a href="https://wordpress.org/tags/phpull" rel="ugc">PHPull Support Forum</a></li>
</ul>
Change Log
<ul>
<li>1.0 – Support for Firefox 2/3, IE 6/7/8, Safari 3/4, class support</li>
</ul>

PHPull

Easily reference a PHP function and have it displayed in a styled tooltip on hover.

QR Code Tag vs PHPull