We have found that firewalls with application control are better at blocking Trojans than are firewalls that block only ports. That's because Trojans can operate by making outbound connections on common ports. Firewalls alone, however, won't protect against viruses. For this, you need antivirus software, preferably a package that checks often for new signature definitions.
SECTOR SLACK: Say a volume uses a cluster size of 64K, and a user stores several files, each 40K. When Windows 2000 allocates space it gives each file its own cluster, with the space left over being--you guessed it--sector slack.
Voice analysis seems like a nice option, as many laptops have a microphone port, but can be problematic. In noisy environments, for example, the computer might not pick up the sound, and laryngitis or a bad cold might lead to a frantic helpdesk call.
As for connecting to the corporate network, two words: Use encryption. First, determine what needs to be encrypted. If all your users will do is access Web-based programs, you can get away with HTTPS. You can also encrypt e-mail by using SSL over IMAP or POP3, which makes sending and receiving e-mail over the Internet more secure by encrypting the entire session, from host to e-mail server (for a secure appliance e-mail solution see "In the M2000, Mirapoint Makes a Mighty Message Server"). There are two major forms of e-mail encryption, S/MIME and IMAP/POP3 over SSL, and they serve two different needs. S/MIME encrypts or signs the message, but not the session. IMAP/POP3 over SSL secures the login and session, but on the next hop the data can be transmitted in plain text. IMAP over SSL is very simple and requires no user intervention, but not all client software supports it. If you want all your traffic to be encrypted, or if some of your programs do not support encryption, a VPN is the way to go. Virtual private networks let remote users access internal resources without making these resources publicly accessible. (For more on VPNs, see "Add Some FiberLink to Your VPN Diet.")