If you are a start-up company that does not require intensive computing resources, you can easily design a full office computing network, complete with resilient backups and Disaster Recovery, for both low upfront and monthly cost.
The traditional model of having a server or two in house to serve files mail, security and backups is no longer necessary. There are appliances that serve files, handle your firewall, detect intrusions, filter filtering and secure your computer systems. Most if not all of them, can also be installed as software running in the cloud. Software packages are available that can encrypt and backup your file-server appliance into the cloud (S3, Rackspace, etc), giving you nearly unlimited backup storage medium for extremely low rates. There are software packages that can be installed on every client computer, allowing an external IT person secure access to the computers to fix helpdesk-related issues. Mail service is readily available in the cloud from a variety of providers (e.g. Google, Rackspace etc.).
