Google Earth. It's been around forever. I can get my property view from my county assessors site. Includes historical view and current within the last 4 years.
I saw the Street View car go by last summer. The view is recent but Google Earth for my area is not. Plus, my lot is bisected by one very old and fuzzy google earth shot and a newer (but still old), and a bit less fuzzy image. The usefulness of Google Earth varies.