A small collection of collections

Some of the interesting things I've run across in past weeks:

• Wikimedia Commons - a collection of "public domain and freely-licensed educational media content (images, sound and video clips)"
• Springfield Township High School Virtual Library's "New Tools" - a collection of everything from polling and survey tools to eBook and iPad info.  Lots to look through!
• Mashable's "5 Free Tools for Creating a Screencast" - a collection of free screencasting tools (plus short reviews of each)
• "10 Twitter Features You May Be Missing" - A collection of features that you may be inadvertently ignoring (I found at least 2 that I had overlooked and was glad to know about!)  I've also run into some Twitter terminology lately that I needed to look up, leading me to Twitter FAQ: RT, HT, OH, ETC - a collection of Twitter "Frequently Asked Questions."
• Bathroom Newsletters - A collection of feedback on the topic of newsletters for bathrooms.  Really.  (Totally not a "tech" collection, but I'm including it anyway! I hadn't really stopped to think about the possibilities before, but when I ran across this, I thought about how some restaurants actually put advertising in stalls.  Advertising that businesses PAY to put there.  Opportunity?  Captive audience?  Hmm....) 

What interesting things have you run across?