Sometimes when you're designing something, you need little helping hands. Perhaps a nice stock photo. Perhaps a happy little color palette. Perhaps a bleep or bloop sound. Perhaps the perfect icon.
There are tons and tons of sites that do those things. There are fewer sites that curate these design resource sites into manageable, high-quality groups. So allow me to abstract that yet another step and provide a selected list of those types of sites.
This is the one I was trying to remember the other day that spurred the idea for this little post. I quite like how you can just hang out on this site and click around to what you need by the type of resource, and the resource sites themselves just come up iframed.