I have a number of websites that I host with my own hardware. This site not being one of them but I am always looking for ways to improve the security on sites I do host and I have been pretty lucky. My thought process has always been If someone wants in bad enough they are going to get in. The key is keeping data backed up and the truly important stuff on machines that only get connected to the net to get sec updates etc.
I received a press release about a new service for people that have the opportunity to stick a machine outside your firewall running a cool applet. The site and software have rcvd a good review on InfoWorld So if your worried about your servers check out the tool they have created. www.descan.net also they have a July 22 Press release