The showcase is over and we've had a bit of postmortem via email which boils down to:
1) Before committing to a date make sure that there are enough bodies available to help clean up (if it takes place in our space - Language labs or CALL). This needs to be as integral to the planning process as anything else.
2) Order the food early. Catering responds very well to early orders and, not surprisingly, not as well to late orders.
3) Make sure that at least a few people are taking pictures, and that they know how to get a good picture in the space used (e.g. in the CALL a flash is absolutely required).
4) Delegated tasks need to be arranged well ahead of schedule. Things were a bit tight for some (especially those running multiple displays) due to a lack of communication regarding what tasks were outstanding.
These are the tasks I know. Any others?