United Cavers Exploration Team

Just an Idea, how about creating a shared Google calendar for all the events?

nice simple idea and i did set us up a google account for exatly that reason some time ago but the difficulty lies in the integration with the database for access tiers - i.e. member / not member, public/private trips. I've had a go with a few calender plugins on the new build so there will be something working all being well. :-)

I have used a couple of good extensions for calendar & booking I use

http://joomdonation.com/components/events-booking.html

It allows you to book on an event so you can restrict numbers if require, there is a waiting list and paypal integration (if payment is required) & email Notifications, you could possibly use it for online membership but I use RsFormPro

http://www.rsjoomla.com/support/documentation/view-knowledgebase/21-rsform-pro.html

Which also has Paypal integration.

They are not that expensive and will save you lots of time, as most of the free stuff has far to many limitation and no support.