Fax machines that double as copiers, printers and even scanners have become extremely popular with people who work at home. Not only do they save space, but they also provide a viable cost-saving alternative to buying four different machines. However, multifunctional machines can also suffer from perpetual mediocrity--while their overall performance is adequate, no one function is top-rate. Make sure you're comfortable with all of the trade-offs. Also, since most of the functions work off the same technology, if one segment of the machine breaks down, you're out of luck all around.
A fax machine can also double as a telephone. If you plan to use one line for both your phone and fax, models that offer distinctive ring detection might be useful. This feature distinguishes incoming faxes from phone calls and will ring differently depending on what kind of call it is. This way, you'll know if the call coming in is the conference call you're expecting or the signed contract from your newest client. Before investing in such a model, however, make sure your local phone company supports this feature.
High-end fax machines offer an even larger menu of advanced features, but most are best suited for a larger, corporate environment. For most home offices, the cost of buying a model equipped with these features will outweigh any benefits.