hi, i am new to ubuntu and would like to know about security programs in general. in windows, a firewall and a real-time residential antivirus is recommended. is this also the case in ubuntu 8.04 hardy heron? we already have firestarter as a firewall and clamav as an antivirus, but don't know how to verify if they are serving their function. can other av's be installed and ran as on-demand scanners without conflict? how is this done? newbie-newbies here.