Nikolai,

Thanks for your great work on ProfilesX and Calendar widget - using them both and am very happy with them.
If you are considering some other features/application suggestions, I'd like to request profile-changer that's based on calendar events.
I really miss this feature from Symbian, where nearly every profile changer had this implemented. And since you're now familiar with both calendar and profiles API, I can't think of person that would do this better.
Don't know how this feature is usually implemented, but the simplest I can think of is:
1) Write a daemon/utility that starts once/twice/[some times] a day and on startup.
2) The daemon would find all calendar events (for the following day) that contain provided strings and grab their start/end time
3) Schedule profile change event to provided profile at event start time
4) Optional - save active profile somewhere
5) Schedule profile change event to default profile (or previously saved active profile) at event end time.

This can also be implemented as a feature for your calendar widget. It shows forthcoming events successfully - so you've got point 1) implemented already.

Implementing such feature would give profilesX much better chances in the competition with tweakr =)