online booking or scheduling of services with calendar features in CI

[eluser]justdo[/eluser]
Have you integrated online booking or scheduling of services with calendar features in CI?

say you have 3 capacities: capacity1, capacity2, and capacity3 and two week out schedule in which each day offers four time slots and users can see calendar and reserve or book any open time slots.

I came across this some scripts:

http://websiteclub.skagerak.org/booking/...ness/index (CI based)
http://www.cecilieokada.com/blog/downloads/#booking (CI based)
http://www.viewnepal.com/portfolio_booking_system.php (not sure)

I would like to hear from those with commercial examples. What works, what does not?

[eluser]justdo[/eluser]
anybody home?