Making time to catch up with people at a conference I am attending a number of short (two and three day) conferences this fall. In the past I have scheduled meetings (e.g., time to chat and catch up over meals and coffee breaks) with people prior to the conference in an attempt to maximize my ability to catch up with colleagues/friends. This approach, however, doesn't work for me. To often meetings get cancelled and if I fill in my schedule too much it is hard to reschedule. Other times I have taken the play it by ear approach and catch up with who I catch up with.

Is there a good strategy for catching up with colleagues whom you already know well (I am not asking about strategies for meeting new people)?
Skip the talks

Except for meals, most of the time at a conference is taken up by scheduled talks. Don't go to them. 

Ok, go to some of them. But if you want to get some work done, catch up with a colleague during a coffee break, take a look at the schedule, find a session (or two, or three) that seem extra boring, and agree to skip them. Use that time to go to a coffee shop, or sit in a quite space in the conference center.