Hi!
You can use a cell phone as your business line or you can look into pbx services (which could forward to your cell, landline, etc) like, RingCentral, My1Voice, Onebox for a small monthly fee. What is nice about these services is they offer call forwarding, 1-800 numbers at no extra charge, caller directory, voicemail, email notification of voicemails.
Here is one site that compares:
http://www.pbxcompare.com/virtual-phone-numbers
Good Luck!