David Spinks has a fun tradition for the CMXSummit.
Everyone jumps up and applauds speakers as they walk on stage.
It's fun for participants and a buzz for speakers.
Some communities (especially those we're involved with) ask members to share their biggest mistake.
It breaks down emotional isolation from the community. It typically gets a good response. It's interesting to established regulars. It facilitates bonding. Sharing the biggest success/fear can work just as well.
Small, exclusive, communities can profile newcomers or invite members to share their thoughts on one particular issue.
This thread on Reddit documents an array of hilarious, shocking, gross, and unique rituals.
Every community would benefit from having a ritual newcomers go through. Avoid the shocking and go for something fun and interesting. Try to get members emotionally invested in the community.