Depending on how accurate you need the current value to be, you have several options.
The least accurate would be going to a site like Zillow.com or Eppraisal.com. Both provide automated valuations based on public records. Neither factor in personal inspections of the home, the comps, their condition, etc.
More specific would be an agents Comparative Market Analysis or a full out appraisal. Depending on why you need to know and how accurate you need it to be, any of these may be useful.