On June 1st FFII are organising a swpats conference, and on June 2nd The Greens/European Free Aliance are organising a "Free Software Vs. Software Patents" event - both in the European Parliament.
Richard Stallman and Alan Cox are the keynote speakers for the June 2nd event. Registration is required for both.
June 1st registration form: http://demo.ffii.org/bxl0506/ June 2nd registration form: http://greens-efa.org/pdf/agenda/Freesoftwareandsoftwarepatents/index.php
There will also be a march/demonstration on the evening of June 2nd, and a Freedom Party hosted by FSFE.
The registration form for the June 2nd conference says that Today (Friday 27th) is the last day for registering. I'm not sure if that's true, but anyone coming should register asap.