You can find the roundup of other convention ideas here.
When we plan convention events, there's a tendency to keep events focused ON the convention itself – doing things there at the hotel, building, etc. You paid for that floor space, youíre going to bloody well use it.
Floor space aside, for professional events, you might want to think out of the box (or the hotel). Depending on where your convention is located, you may want to think about doing some professional events outside of the convention.