Few quick reminders, seeing as they have not been covered in this thread:
-Please wash your hair sometime before the meet, if possible.
-Please kindly refrain from use of hair styling products (i.e. hair gel, hairspray, mousse, etc.).
-If you're bringing gear, try to bring a power strip with you.
-If you're bringing headphones/amplifiers, also please bring a source. An issue I've encountered at some meets is a lack of sources.
-If you have a certain musical preference or specific music you'd like to demo on someone's equipment, don't assume they'll have that music. I encourage everyone to either bring music on CDs or thumb drives. External/portable hard drives work as well.