The Open Web Application Security Project (OWASP) is an open community dedicated to spreading knowledge on designing secure computer applications. On the 10th of September 2009 in Trinity College in Dublin, they will be holding their first Irish Application Security conference:
While at their site, please have a browse of their excellent guide to Web Application Penetration Testing:
Their full application security testing guide (~350 pages worth) in PDF format is available for free download here:
Should be an interesting event!