Check out the schedule of conferences for our next Drupalcon Barcelona 2007. We have 84 conferences on a variety of topics, from showcases to API workshops, for any type of Drupal user, from evaluator to core programmer.
Any one can find a topic of interest at any time. There will be 4 rooms which can hold from 70 to more than 200 people plus 7 special spaces for BoFs. Any attendee will be able to propose a Bof at any time.