One of the better attractions of XP2007 was Charlie Pooles idea of an open space event he came up with named: Agile Café.
Since the main conference didn’t have that much to offer and you had to participate in either workshops or tutorials to get something out of XP2007 this was a most welcome initiative.
Anyone who had anything to discuss could put up a small sign, folded paper, on a table with the text “Agile Café”. This worked really well and led to a lot of interesting discussions. Mainly in front of the hotel where there were some 20-30 chairs and a few tables.