This is a fantastic presentation by Steve Taylor at the 2011 Wordcamp UK conference that shares some important information on how to make your wordpress install more secure and faster.
Jim Callender is a Freelance Wordpress Developer. Living & working in Brighton. He started working with Wordpress in 2003. Since then has been responsible for delivering high profile sites for a number of large UK design & marketing agencies. His other site is www.jayonline.co.uk