someone starts a thread showing something and lots of people join in showing their stuff with it

Some of the most fun threads I can remember were when...I think it was Dennis Shoop...started a thread for everyone to show their favorite [yellow] chip...or blue chip...or green chip...or $1 chip...or $5 chip...or.... and tons of chips were posted!!

(that's why I often 'drop in' uninvited to show a postcard or something on someone's "of the day" thread ...a behavior that probably shouldn't be encouraged... )