Learning is so important in my industry (programming and computers in general) that you can never look at a learning opportunity as wasted time. Also it is the Christmas season, and people do Advent things... so I present the Advent list. All these sites have Advents going on that teach tips and tricks for different languages.
- PHP Advent - http://phpadvent.org/2011
- 24 Ways - Design and Developmenthttp://24ways.org/
- Performance Planet - http://calendar.perfplanet.com/2011/
- Ad Font - http://2011.adfont-calendar.com/
- Mozilla Developer Network - http://thewebrocks.com/calendar/
- Perl Advent - http://perladvent.org/2011/
- HTML5 and CSS3 - http://html5advent2011.digitpaint.nl/
- 12 Devs of Christmas - http://www.12devsofxmas.co.uk/
I hope you find these handy, and learn a thing of two!