An important goal of hackerspaces.org is to increase communication and collaboration between hackerspaces, so bigger projects like hackerspace-festivals and support of fledgling hackerspaces become feasible.
The best way to get in touch with hackers from all over the world. Every Jabber account created on jabber.hackerspaces.org automatically gets a contact list of all the other users. Makes for a nice network effect. Note: If you do not see the contact list at first, log out and log back in.
You can also join the Hackers chatroom at xmpp:email@example.com?join
For coordination and discussion purposes we also provide mailing lists. Join our guaranteed low-traffic Announce List (moderated), if you're just interested in updates and event announcements. If you want to actively discuss hackerspaces the Discussion List(unmoderated) is where you want to be. If you want to talk about finance related topics such as fundraising ideas, strategies, member donations, tax laws, join Finance List
Sometimes, hearing a human (or robot) voice just can't be beat. Join the monthly hackerspace Call-in. (SIP Conference Room available via mobile and landlines)
Currently available in English. See that announcement to have your hackerspace's feed included.
Static & Moving Images
Check the Hackerspaces Xchange group for resources to be shared between spaces.
Some hackerspaces are remotely viewable to some extent via Webcams.
http://www.dimdim.com - Open Source webinar software that makes GotoMeeting look like amateurs. This software is hosted by dimdim so there is nothing to download or install. Just sign up for an account. The free version supports up to 20 guests and the professional version ($99/year) supports 100 guests. The software is Flash browser based and extremely fast. Use it to hold classes so that other hackerspaces can participate.
Unfortunately, DimDim has been acquired by Salesforce, so looking for a new solution is recommended!
Not quite "webinar" but free and can be used to share your screen or camera for classes or meetings:
https://www.join.me/ - Has a decent, free option.
http://www.skype.com/en/features/screen-sharing/ - Not sure how much we love/hate Skype but it has some screen sharing that could be used in a pinch.
https://www.google.com/+/learnmore/hangouts/ - Google Hangouts have been used for cases where a hackerspace member was out of town but wanted to attend the monthly meeting.
Hackerspace Mentors - A list of experienced hackerspace members, willing to answer questions and offer advice.