Black hat conference

Black Hat conference, USA 2005 was great one especially after the Michael Lynn presentation on "Cisco IOS Security Architecture" which exposed the CISCO IOS flaw which can lead to DDOs attacks and can give router complete access. The bug is not as serius as CISCO keeps saying and has filed suit against the researcher. Checkout my earlier post

Other one was the highlighting of RFID and VoIP security threats

A lot of other security issues, bugs and holes has been discussed and presented too.
http://news.com.com/Black+Hat+Hunting+bugs%2C+finding+holes/2009-7348_3-5808386.html?tag=nefd.top
http://www.blackhat.com/html/bh-media-archives/bh-multi-media-archives.html#USA-2005