There are many add-ons to FS that *are* based on aerial imagery - I'm
waiting on the one for Northern California to be released by
www.megascenery.com for instance.

I just spent a couple hours last night flying a virtual cross-country in FS
2004 with the MegaScenery pack for Southern California. (It's something to do
until my student pilot/medical certificate problem gets resolved.) It was the
first time I actually used the MegaScenery in a useful way.

I don't like that it takes so long to start up FS when it's installed, and
while the general terrain features are far better than what FS offers by
default, it's still not accurate to the point that a student pilot like me
could use what I'm seeing on the screen and match it to the reality of flying
in the pattern at my home airport.

That said, I found it to be invaluable last night in gauging the effectiveness
of landmarks I had chosen along my route (CCB - F70 - CRQ). Lakes that I
didn't think were very interesting on the sectional really stood out in FS,
telling me that distinctive lakes make very good landmarks (especially when
your path is in between two of them).

I also have the Keyhole software. I bought a year subscription a while back
just for fun. It's great for getting aerial views of particular places (such
as destination airports), but I don't think it would do as well for simulating
navigation, IMHO.

--Marc