Thebigtop is the newest Juggling and Flow forum as of 2022.
Connect Circus is a database of jugglers and circus people around the world.
The Juggling Edge gives an overview of regular juggling groups around the world as well as conventions and small talk. It's completely English language and mostly used by British jugglers from what I read. Sign up is by invitation, only- you'd have to convince The God Emperor Orinoco - it's not that hard!
International Jugglers´ Association (IJA) The IJA is more an american than an international association, but still, to be up-to-date you should read their eZine.
Manipeo A collection of juggling videos and other stuff
JuggleJunction Similar to the juggling edge, this page offers a database on juggling clubs and upcoming conventions worldwide. Additionally, it offers a link to rec.juggling.
rec.juggling Probably the most important news forum for jugglers ever. This link leads you to the google group, so you don't need any adaptor program to open.
JuggleWiki News, mostly about records and championships in English.
Jugglelounge A chat client for the web - if you absolutely MUST talk juggling from everywhere.
Juggling on Reddit And another online community with chat a wiki and more links.
Juggling Lab Another good source for tricks, also animated!
Ministry of Manipulation A page collecting Cirque nouveau videos and stuff...