http://nmap.org/book/man-port-scanning-techniques.html - this page lists technique that allows to probe if a UDP post if closed. It would be awesome to see green button that lights up when you complete IP entry in configuration dialog.
[taken from issue tracker]
for all-in-one calendars like this one link it would be great that when asked for the calendar name you could also specify a filter and only subscribe to event titles matching this filter.
(Other Use-cases might be garbage-collection calendars or sports teams…)