Google Apps Calendar comes with a cool built in feature called "appointment slots". You can easily create blocks of time on your calendar that people can reserve. It's like Sign Up Genius without having to create a separate account!
Here's how it works:
1. You create "appointment slots" on your calendar. You can set individual times or choose a block and tell Google how many slots to divide it into.
2. Share the event with specific people by entering their email address or copy the appointment page URL to send in an email.
Check out the Google help page for step by step instructions on setting up your own appointment slots.