Groups: The Groups feature is available to everyone now. All users have full access to Groups.
Have them look in the green menu bar at the top of any page on Biznik, and they should see "Groups". And the link you are giving them - http://biznik.com/groups/turquoise-tribe - should work for anyone regardless of whether they are even signed up for Biznik or not.
If they are having troubles with the link, it might be a problem with the way the link is formatted, or that their email program blocks HTML links somehow.
Interminable Spinner: I was not aware that you were still having problems with the "process indicator" (the spinny wheel thing), and your browser was not updating... we took care of those problems on our end a while ago.
If the process indicator is not giving you accurate process status, my guess is that either it is an issue with your web browser and system version (what version of Firefox are you using, and what operating system version do you have?), or it could be you have a sketchy internet connection... but that would affect ALL the web sites you visit... not just Biznik.
This is perplexing. Give me some more details, and let's see what we can find... (also would still like to see your computer, next time you are in town).