http://maps.google.com/

Phenomenal interface. Much better (IMHO) than Mapquest. Hopefully the accuracy is improved, too.

It is better, but not perfect, not by a long shot. It is better looking, when you finally get zoomed in enough. However the search engine is horrible. If I can master the search parameters I may just use this more often than yahoo, if it proves to be more accurate.

Unfortunately when it comes to the industry, you can never have a truly up to date data set. As much as Navtech and TeleAtlas work with drivers physically driving the streets it is never correct. OR it is intentionally incorrect. Take it officially from me, WE (the mapping industry) make "mistakes" intentionally. This is the way we catch the cheaters that are copying our work. A unnamed photoshop in GE was caught doing this just last year by me.

So if for some reason you see a Godiva Park, Connor Park or a Home Dr on a map where it shouldn't be, it may be wrong but it is there for a reason.

Here's an interesting semi-technical analysis of how Google maps does its magic inside the browser:

http://jgwebber.blogspot.com/2005/02/mapping-google.html

(This doesn't address the mapping issues mentioned above, though.)

And here's a discussion on Slashdot about Google maps:

http://developers.slashdot.org/article.pl?sid=05/02/09/1836256&tid=217&tid=8

I find this and the stuff posted above about mapmakers filching work from other mapmakers fascinating.

EDIT: Try searching http://maps.google.com for "insufferable whiners in Washington, DC" (literally).

Funny stuff, but a sense of humor is recommended.

Last night, Google added satellite imagery for most of their maps. Click on the 'satellite' link in the upper right corner of the browser window.

Very cool. Not all the country has the detailed imagery, but it looks like Glen Ellyn is zoomable to the highest level of detail.

Amazing level of detail -- you're able to see cars parked in the street, and if you have a lighter concrete driveway, you can probably see cars your driveway.

http://maps.google.com

For satellite images, I'd suggest Terra server. You can also toggle between different satellite images and (usually) USGS quadrangles depending upon the zoom factor your on at any particular time. They also have three image size choices and you can "download" the image into one nice JPG.

Pretty cool.

2nd Middlein87's TerraServers' imagry. Last time I was there and zoomed onto my house, I could see the back patio, with our white table in the middle of the patio, and also the plant on the white table. I could also clearly make out the white RocketBox I have on top of my van. Amazing. Makes me wonder what kinda detail the military has going for them.