Most of my friends are in there are twenty/thirty something and have quite a busy (social live). Making appointsments can be quite cumbersome, especially when multiple people are involved. Fortunately, there's electronic help, there are websites were you can schedule appointments. I've used the Dutch sites Datumprikker.nl and the fairly new startup Pleft. Although there both quite easy to start using, I'm far from satisfied. Datumprikker and pleft both have quite limited functionality. The only thing you can enter are available dates and a list of contacts/emailaddresses with whom you want to make an appointment.
What would like is integration with my electronic calendar of Google Calender (personal) and MS Exchange (work). That way, almost automatically available dates could be picked. Both Google Calendar as the latest version of Exchange can make there calender available via ical - so integration should be quite easy. When all people you want to make an appointment with have there calenders integrated as well with the appointment tool, an appointment could be created automatically - just like a secretary would do by calling other people's secretaries.
Furthermore, besides entering emailaddresses, picking contacts from my address book from either google or MS Exchange would be more convenient.
I was thinking, such an application shouldn't be hard to make. I wasn't the only one with that idea. Recently someone suggested another website: Doodle. From what I can see, that website seems a whole lot better than there Dutch counterparts. Integration with Google Calendar and Contacts. Integration with Exchange and possibility to add ical calenders. Looks good, saves me from creating a startup ;-).