What phone systems do you use for your business?
CyberFonic: I used to maintain PABXs for small businesses.  Pre-VoIP PABXs are expensive, inflexible and expansion often traumatic.  Enterprisey VoIP systems from major vendors are over-priced and they get you on the extras.  I recommend hosted VoIP for those who don't want to administer their own phone system and in-house VoIP for those who want a bit more control. FreeSwitch is very good solution as well.  Don't get any POTS lines, use the money you save to get a fatter IP pipe into your office.  Most VoIP handsets are fine, I don't think CISCO being worth the premium.