I try to keep a file of ideas—visual and written—to help when I'm stuck. In the past year I've gotten pretty lazy about updating. I suppose I lose too many glue sticks. That's why I'm really excited about Image Spark.
It's your own virtual library that allows you to tag any images you find on the web and add them automatically to your Image Spark page. No more oversized InDesign files and no more lost scraps of paper—it's all in one electronic place. Wahoo! I just started this, so I don't have much, but I can see how it will become quite addictive. Check out my library! and then make your own.
Speaking of ideas and inspiration, if you can't make it across the pond, you can visit the London Design Museum's design library for information on an infinite number of designers and projects. It's a great resource if you're interested in finding out more about any well-known person in the industry.