There's an excellent online QR generator at qrhacker.com that lets you create colorful QR codes and what makes this tool different is that it provides you can option to embed photographs and logo images to your QR codes. You can even edit the colors of individual pixels that form the code.
180 Technology Tips is a great resource for educators. It sends out an email everyday with a 5 minute lesson on some aspect of technology. You just sign up using your email address and it does the rest. Topics include better web searching, Microsoft Word and Excel tips, email, toolbars, cellphones, and more. The site also has past lessons archived for you to look at. I found the lessons easy to follow and understand and recommend this to all teachers.