Jiffle is web based but there is integration available for both Outlook and Google Calendar. The premise is simple enough. You tell Jiffle when you're available and then share your availability. You can share it either publicly or with a set of contacts. When someone needs to schedule a meeting with you they can see instantly when you're available. They don't need a Jiffle account, just the URL you share with them. From there they can pick a time, enter in their contact info and notes, and the request appears in your email inbox.
When you accept a potential meeting time your calendar is populated with the information from the other party and your own additional notes if you've added any. Other users only see when you are available, no other information about your calendar is shared. If your problem isn't scheduling snags when dealing with one on one meetings but trying to get your whole department together at an optimum meeting time, make sure to check out previously reviewed solutions like WhenIsGood and Congregar—both are focused on finding the best time for groups of people. Jiffle is free for individual use.