1) The space is adequate if your appointments tend to be short eg Bob and Cathy or lunch and not complex like Bob, Cathy, sys-eng group rep. re: develop timeline to cost out and deploy new server cluster for foobar project (see 3/10/2010 emails "foobar server" and 3/5/2010 "how do I price a webserver?". 6th floor conference room (call in number 1-888-555-1111 p:142678)
2) The downside of any paper-based time planning is that it gets messy if you need to change things very often.
3) If you have overlapping appointments very often then I think you need to fix a more fundamental problem with your scheduling.
Unless you are some sort of genius, it seems really unlikely that you can seriously pay attention to more than one thing or person at a time. By trying to split your attention, there's a good chance you are less useful than you would be if you told one of your appointments to take a hike.