@ Tridion - if you mean the events forum set up by RateU and as the example he has posted here, then what you COULD do is use the signup sheet that was made for 1.4. That allows you to add a sign up sheet to a calendar event. Then you can have the event details in the thread (as done by RateU) and a link to the signup sheet in the calendar.
Very quick example here:
http://www.leefish.nl/testfish/showthrea...http://www.leefish.nl/testfish/showthread.php?tid=30&pi >> click on signup
You can use the testuser log in
testuser
testuser1
This would require the thread creator to make the calendar event etc themselves, but its easy to do, the sign up form could be configured a little better too.