Come, take a ride and look at some of the Islamic Art of the past. Or, you could call it Art of the Islamic World if you're so inclined. If not, then how about taking into account some of the major milestones of Islam throughout the centuries, from past till present (more examples here), including the art of Calligraphy and Architecture. Not to mention the Arab world's contribution to music, both old and new. [Previously mentioned, here, here, here, and here, with a wonderful comment from nickyskye as usual]
posted on May 29, 2008 - View this thread

Speaking of speeches, David Eggers delivers one at TED on grassroots community tutoring for kids who need help with their English homework: "There's something about the kids finishing their homework in a given day, working one on one, getting all this attention. They finish their homework, they go home -- they're finished. They don't stall. They don't do their homework in front of the TV. They're allowed to go home 5:30, enjoy their family, enjoy other hobbies, get outside, play and that makes a happy family. A bunch of happy families in a neighborhood is a happy community. A bunch of happy communities tied together is a happy city and a happy world, right? So, the key to it all is homework." Love him or hate him (mefi consensus) it's a great example of nervous energy microphilanthropy, social entrepreneurship and, if I may make the connection, machines of loving grace. [previously]
posted on Mar 23, 2008 - View this thread

The Last.fm guys really wanted a ballpit, inspired by the xkcd blog. Pictures.
posted on Jan 16, 2008 - View this thread

To build a better mousetrap.
posted on Oct 24, 2007 - View this thread

Super(-expensive) Playgrounds are nice to look at, but what makes a playground fun? Experiments in play: Snug & Outdoor (1, 2, 3) Mcdonald's (1, 2, 3) KaBOOM! (1, 2, 3) Boundless Play (1, 2, 3)
posted on Apr 22, 2007 - View this thread

Tryangle cannot be defined, but it's way fun. Use it to easily create angular art pieces, then share your creation with the teeming masses on the Tryangle Flickr pool.
posted on Dec 1, 2005 - View this thread

myData=myMondrian is an interactive art interface in which the personal data provided by viewers is translated into a Piet Mondrian-like composition. Here's an example image.

Related: Rhizome.org: myData=myMondrian
posted on Apr 8, 2005 - View this thread

Bagophily. Extensive collection of airline sick bags.
posted on Dec 12, 2003 - View this thread

MetaFilter as a ransom note. Crazified by crazy sites. [via Adactio]
posted on Nov 16, 2003 - View this thread